MPs' expenses: Cameron considers removing whip as Brown says sorry

David Cameron was last night ­considering removing the Conservative whip from some of the most senior party ­backbenchers in the wake of allegations that they have abused the MPs' expenses system to build swimming pools, improve their second homes, and even buy horse manure at the expense of the taxpayer.

The Tory leader was informed yesterday afternoon about some of the allegations. His spokesman said last night he was appalled at what he had heard, and was considering his disciplinary options.

A spokesman for the party said: "David Cameron can, with the agreement of the chief whip, remove the party whip from these people; and there is no doubt he will do this if he thinks it is appropriate." Three Tory MPs have responded to the allegations by admitting culpability, saying they would repay the expenses they claimed.

Cameron's initial tough response came in the wake of the first opinion poll that suggested the Tory party was being damaged as much as Labour by exposure of MPs' expenses claims. A Times/Populus poll showed Labour support down four points since early April to 26%, just above its lowest figure last summer. But the Tories are also four points down at 39%. The Liberal Democrats are up four points to 22%, their highest for nearly four years. Alarmingly for the Conservative party, the bulk of the poll was done before allegations against Tory MPs were published.

If he decides to remove the party whip, Cameron will be taking a huge risk with his personal authority since he will be disciplining some of the most senior backbench figures inside the party. They include: former agriculture secretary Douglas Hogg; Tory chairman of the defence select committee Sir James Arbuthnot; chairman of the 1922 Tory backbench committee Sir Michael Spicer; leading eurosceptic David Heathcoat-Amory; and former Conservative chairman Michael Ancram.

Questions were also being raised by the Daily Telegraph, on the basis of its access to MPs' expenses forms, over claims made by the former shadow home secretary, David Davis, who challenged Cameron for the party leadership.

Hogg submitted a claim form for more than £2,000 to pay to clear the moat around his country estate. Sir Michael Spicer, claimed £5,650 in nine months for his garden upkeep. Michael Ancram claimed more than £14,000 a year in expenses while owning three properties, none with a mortgage, and are together worth an estimated £8m.

It was also claimed that deputy speaker Sir Alan Haselhurst claimed £142,119 for his country home over the last seven years, despite having no mortgage. He had been seen by some as candidate for the speakership if Michael Martin stood down before the election.

Martin yesterday astonished some MPs by rounding on critics in Westminster, including Labour MP Kate Hoey, accusing them of voicing their concerns by going to the press.

So far Cameron has decided to take no action against any of his shadow cabinet and has defended Andrew Lansley, shadow health secretary, and Michael Gove, shadow children's secretary, from claims of "flipping" their homes .

Gordon Brown also responded yesterday to the systematic flouting of Commons expenses rules by offering his own unreserved apology todayon behalf of all the political classes at Westminster. It is the second public apology the prime minister has been forced to give in a month, following his regret over leaked emails showing his former aide trying to smear the Conservative leadership.

There is also a general fear, including among the Liberal Democrats, that it will be parties outside Westminster ranging from Ukip to the Green party and the British National party that will be the big beneficiaries at the European elections on 4 June.

In the first signs that contrite MPs were taking unilateral steps to protect their ­reputation, one leftwing Labour MP, Ronnie Campbell, announced that he would try to set an example by paying back £6,000 in claims for furniture. John Mann, another Labour backbencher, said MPs should have their expenses cut. He also called for the Speaker to quit if he would not lead the campaign for reform.

In an effort to quell public anger, Brown offered a clear apology and pressed for an early report by the Commons committee on standards in public life. He said: "We must show that we have the highest standards for our profession. And we must show that, where mistakes have been made and errors have been discovered, where wrongs have to be righted, that that is done so immediately.

"We have also to try hard to show people and think hard about how a profession that, like yours, depends on trust – the most precious asset it has is trust – how that profession too can show that it is genuinely there to serve the public in all its future needs."

He also said: "I want to apologise on behalf of politicians, on behalf of all parties, for what has happened in the events of the last few days."

Brown urged his MPs to show discipline and unity, insisting that by the time of the general election the voters will be making decisions on the basis of big economic divisions between the parties.

Many Labour MPs have expressed their anger at what they regarded as the partial and distorted way their expenses claims were being reported in the Telegraph day after day.

In an attempt to end the drip-by-drip damage on Westminster's integrity and reputation, the Commons committee responsible for expenses met to see if it should bring forward its planned publication of claims dating from 2004-08. But it rejected a radical acceleration. Nick Harvey, a Liberal Democrat member of the House of Commons commission, said it would bring forward the formal publication of MPs' expenses from July to next month, if it could.