Hundreds of British tourists have been caught up in protests which yesterday shut down Thailand's main international airport and pushed its government to the brink of collapse.

Hundreds of British tourists have been caught up in protests which yesterday shut down Thailand's main international airport and pushed its government to the brink of collapse.

Several hundred Britons were among an estimated 3000 people who became stranded at Bangkok Airport after it was occupied by the People's Alliance for Democracy (Pad), which wants to topple Thai premier Somchai Wongsawat, brother-in-law of the exiled former prime minister and one-time owner of Manchester City Football Club, Thaksin Shinawatra.

As all outgoing flights were cancelled yesterday, exhausted travellers could be seen sleeping on their suitcases, luggage carts, security conveyer belts and behind vacated check-in counters. Protesters dressed in yellow shirts walked around distributing food, ham sandwiches and packets of rice.

In a significant intervention into an escalating political crisis, the head of the country's army, Anupong Paochinda, last night called for the government to step down, though he sought to quell speculation that he was preparing a coup.

Arriving back from an Asia-Pacific summit last night, Mr Somchai rejected the calls to step down. Speaking in a television address, he said: "I reassure the people that this government, which is legitimate and came from elections, will keep functioning until the end. My position is not important. But democratic values are."

Foreign Office Minister Bill Rammell expressed "deep concern" about the latest developments.

"We urge all sides to this political dispute to resolve their differences peacefully and legally, respecting Thailand's democratic institutions," he said. "Thailand is an important destination for British tourists and investors. I sympathise with those whose travel plans have been disrupted by the closure of Bangkok's international airport."

He urged tourists to monitor the FO's website for advice and keep in touch with their airlines and tour operators.

The latest demonstration began on Tuesday when a sea of yellow-clad protesters, armed with batons, staged a sit-in at Suvarnabhumi Airport and demanded that flights be cancelled. It was the most audacious move in a four-month campaign topple the democratically-elected government, which Pad's leaders accuse of corruption.

The action coincided with more violent protests around the country, which saw an anti-government activist shot dead in the northern city of Chiang Mai yesterday, following a shooting on Tuesday which saw 11 government supporters injured.

In a country which has a long history of elected governments being toppled by a powerful military, including the 2006 coup which unseated Mr Thaksin, speculation has been mounting that the latest protests are intended to provoke a further coup, under the pretext of restoring order.

At a press conference yesterday, Mr Anupong laid out a compromise plan, calling for protesters to leave the airport and for the premier to step down and call a snap election. But he was widely seen as being sympathetic to Pad.

Pro-government supporters, who have staged their own counter-demonstrations in response to Pad, responded angrily to the suggestion, saying that if Mr Somchai quit they would regard it as a coup and immediately launch anti-military demonstrations.

One senior member of a pro-government group, the Democratic Alliance against Dictatorship, told Reuters news agency: "There will be war for sure if the premier steps down."

Leaders of Pad have vowed to bring its campaign to a final showdown this week.

Having had their flights home cancelled, some of the Britons were being taken by coach to hotels, including in the resort of Pattaya.