SIR John Major accused Gordon Brown's aides of "lying" to the media when their boss was prime minister, it emerged yesterday.

The former Conservative leader even wrote to Downing Street in protest at the smears against him.

Earlier this week Mr Brown denied on oath to the Leveson Inquiry into press standards that he had ever authorised his spin doctors to brief against political opponents.

But the inquiry heard yesterday that in 2008 Sir John was so incensed by one set of newspaper claims that he wrote to the prime minister's office to protest.

In the letter, he accused Mr Brown's team of repeatedly lying to the press and threatened to expose those responsible if it happened again.

The letter, released as part of Sir John's evidence to the Leveson Inquiry, reads: "This sorry episode raises – yet again – the extent to which those around Gordon Brown both as chancellor and now PM are willing to lie – and I do not use that term lightly – to the media for party political advantage."

Sir John told the inquiry the letter had also made clear that if he was the subject of similar briefings again "I would go public immediately and I would name the adviser concerned".

During his evidence to the inquiry on Monday, Mr Brown, Labour MP for Kirkcaldy and Cowdenbeath, denied authorising his staff to give negative briefings against others.

The 2008 stories claimed that the former Conservative leader had intervened to try to ensure disgraced Zimbabwean leader Robert Mugabe kept his knighthood.

But Sir John had also felt he was the subject of malicious briefings in 2005, he told the inquiry. Then, he had been subject to headlines suggesting he was blocking the release of official papers about Britain's dramatic departure from the European Exchange Rate Mechanism in 1992.

The story was "utterly untrue" and he was "very angry", he said, describing the briefings as "totally dishonest and potentially damaging".

After his letter, Sir John was told by a senior official that the issue would be raised with Mr Brown. "But that was where it was left," he told the inquiry. On Monday Mr Brown denied authorising briefings against other politicians including Tony Blair and Alistair Darling.

He dismissed allegations of negative briefings as "gossip, rumour, innuendo" in Westminster.

But he admitted that other MPs had warned him about one of his aides, Damien McBride.

Mr McBride was later forced to resign when it was revealed he was constructing plans to smear senior Conservatives and their family members.

Current Labour leader Ed Miliband appeared to question Mr Brown's statement that he was unaware of briefings by his advisers against Tony Blair.

Mr Miliband told the inquiry that Charlie Whelan, one of Mr Brown's closest advisers, had left his job partly "because of his style of operation".

He said: "I can't point you to direct evidence but I would say one of the things he did was he briefed, including potentially against people in the Government."

Sir John also told the inquiry that newspaper owners should be held liable for all stories in their papers, accusing them of behaving like "Pontius Pilate" and washing their hands of what was going on below them.

He admitted he had been "much too sensitive" about his treatment from the press, who once described him as the kind of man who would tuck his shirt into his underpants.