The threats began just hours after President Mohammed Mursi was deposed.

A steady stream of insults and gruesome suggestions sent to her mobile phone and posted online. Some vowed murder; at least one threatened sexual assault, she says.

Azza Al-Garf is one of the better-known figures in what, until recently, seemed Egypt's most successful political party. A member of the Muslim Brotherhood since her teenage years, the 48-year-old was one of just nine women elected to Egypt's first post-uprising parliament in late 2011. Before long, her deeply conservative views on women's rights made her anathema to the progressives who had played a major role in toppling ex-president Hosni Mubarak.

Now, like many in the Brotherhood and its political wing, the Freedom and Justice Party, she's on the defensive. Harassed by what she believes is state security, she claims a plot is under way to overturn democracy and send the once-outlawed Islamist group's leaders back to prison.

"It's a complete military coup against democracy. Egyptians had agreed on the ballot box and the majority gave their votes to Mohammed Mursi," said the mother of seven, sitting on the patio of a social club in one of Cairo's satellite cities.

"This last week we've returned to the Nasser era. We've had political arrests, the closing of television channels. There's no freedom of expression anymore."

Such is the view inside the Muslim Brotherhood, one year after Mursi narrowly clinched the presidency in free elections – and just over a week after millions of protesters in Egypt's streets prompted the military to force him from office.

Authorities have sealed the Islamist organisation's buildings and closed its TV channel and other stations deemed sympathetic. Hundreds of arrest warrants have reportedly been issued and several senior members detained – a necessary measure, prosecutors say, to quell future violence and investigate fatal attacks on anti-government protesters.

Also sending shockwaves was a fatal crackdown on pro-Mursi demonstrators encamped outside a military facility in Cairo early on Monday morning. Over 50 were killed and hundreds wounded in what the Brotherhood and other eyewitnesses said was an unprovoked attack, but which the army has repeatedly claimed was a response to "terrorists".

Just days before, seven died in El-Manial, an island district in Cairo, when armed Islamists attacked residents trying to stop a passing pro-Mursi march.

When Mursi took an informal oath before a packed Tahrir Square last year some thought it heralded the beginnings of fully-fledged Islamist rule. But it wasn't long before dissent bubbled over, with critics accusing him of forcing through a discriminatory constitution and using Mubarak-style brute tactics to smash popular protests.

Others complained the president tried to muzzle the media and that his pandering to hardline Islamists helped fuel recent violence against the country's Christians and Shia. Through it all Egypt's economy lurched further into crisis.

No-one knows exactly how many took to Egypt's streets in the days around June 30, but, outside Brotherhood ranks, it is commonly believed the numbers trumped Mursi's electoral support.

In just one year, the group's 85-year dream of governing Egypt according to strict Islamic principles is crumbling. Signs of Brotherhood decline are everywhere. The group's once-gleaming new headquarters in Moqattam, a suburb on the eastern limestone cliffs overlooking the capital, is abandoned, its six-storeys gutted by looters. On the rooftop sign, the crossed swords and Arabic calligraphy of the group's logo is already scorched and faded.

Mursi himself is said to be under arrest at the headquarters of the Republican Guard, the scene of Monday's deadly violence. Egypt has a new interim president in Adly Mansour, as well as a rough timetable for elections, but supporters of the deposed head of state haven't given up.

Tens of thousands of them remain encamped around Rabaa Al-Adawiya, a mosque in the northeastern suburb of Nasr City. They've been there for over two weeks now, their presence all but ignored by local media, but their resolve hardening as the holy month of Ramadan begins and they glimpse a return to the political wilderness.

A line of glittering bunting stretches across the wide highway, adding an oddly festive touch to the paving-stone barricades and stick-wielding men guarding the sit-in. Behind the lines, demonstrators doze away the afternoon heat in open, makeshift tents, read the Koran or chat among themselves. The holy month's obligatory daylight fast has sapped their energy and temporarily cooled passions. As the sun slips below the horizon, it casts a pinkish glow on thousands lining up for evening prayers.

"Everyone in Egypt chose Mursi, now they want to take these votes and put them under their shoes," said Sami Muhamed Ali, swathed in a dark green robe, a red hard-hat perched on his head. His group, the Gamaa Al-Islamiya, was a late convert to democracy; it specialised in terror attacks until the late 1990s when it forswore violence.

Others claimed no political affiliation but echoed Sami's lines about legitimacy via the ballot box. "Fifteen million people voted for the current system, it's a minimum right that this be respected," said Hisham Nabil, a 32-year-old pharmacist, inflating the figures a touch to bolster his argument.

"These people around you aren't violent, they are committed to peaceful protest, no matter what you've been told. But there is a danger from other Islamic groups – the ones who didn't embrace peace but now see democracy as completely against the Islamists."

Beside a stall selling prayer beads and sandals, Ahmed Zakaria recounted his experience of Monday's fatal clashes. Running to help the wounded, the 22-year-old student of English was one of several hundred captured by security forces and held for three days.

"They think we are all blind followers. They waved a Mursi poster in my face and said 'this is the great sheep'," he remembered with a shy grin. "One of the officers said to me, 'if you were eating a sandwich and discovered it was rotten, would you keep eating? That's how they justified removing Mursi before the next election."

An older man leaned in as Ahmed finished his story. "The real struggle here isn't between Islamists and secularists, it's democracy versus dicatorship," he said grimly. "We're afraid the police and security services are back for revenge."

The Brotherhood's message has failed to catch on elsewhere in Cairo, where Ramadan celebrations have been buoyed by what's seen as a victory for the popular will. The 15-minute taxi ride between Rabaa al-Adawiya and the city centre seems increasingly like a commute between two distant planets.

On the streets around Tahrir Square, vendors sell portraits of the defence minister General Abdul Fattah al-Sisi, white-clad police officers guard the intersections and traffic putters by in the sluggish hours before Iftar, the breaking of the Ramadan fast.

Banners still hanging on street-lights demand Mursi's resignation; others condemn the US government – widely believed here to back the Brotherhood – whilst praising the US people. Trucks crammed with riot control forces sit quietly on the side streets. In the last two years their presence inspired fear or hatred among revolutionaries, now they stand apparently ready to protect anti-Mursi demonstrators.

But as the interior ministry and army regain their lustre, other parts of Egypt's revolutionary story look like being whitewashed. Military involvement in politics stirs uncomfortable memories of their 16-month rule after Mubarak left office, a time wracked by periodic bloodshed. Some anti-Mursi demonstrators maintain the army has learnt its lesson and committed to a quick, civilian-led transition, others claim that the Brotherhood was to blame all along.

"You're going to hear a lot of wild accusations these days," sighed Mohamed, a media consultant in his 30s watching the fireworks crackle in the night-time sky above a packed Tahrir Square. "I'm glad Mursi is out, but people will try to pin everything that ever went wrong on him."

The fall of the Brotherhood was a victory of the Egyptian people over religious fascism said veteran activist Haitham El-Shafaw, but he warned that the country's largest Islamist movement should be included in whatever comes next.

"They are a huge slice in the nation that we can't marginalise," he said on his way to a meeting of the June 30 Front, an anti-Mursi group. "We are waiting for justice and for guaranteed fair trials for Mursi and his administration. Once this happens there will be reconciliation."

But the demonstrators still camped out at Rabaa al-Adawiya are unlikely to take kindly to such offers.

Addressing the pro-Mursi sit-on on Friday, Islamist preacher Safwat Hegazy vowed the Brotherhood would die as martyrs in their bid to return their man to the presidential palace.

His words found willing agreement in the crowd: "We are here until victory, until Mursi is back in power. There is no alternative."