The Westminster anti-sleaze watchdog looks almost certain to launch its own probe after the surprise move by MPs to cling on to their controversial second homes allowance.

Sir Christopher Kelly, the chairman of the Commons committee on standards in public life, has repeatedly warned he would review MPs' expenses if their own inquiry did not calm public anger.

Asked about the Commons' decision to reject a series of reforms, he said: "I would expect the public to react very badly."

His comments came after MPs defied uproar over their taxpayer-funded claims for kitchens, bathrooms and plasma televisions.

While voting to keep the £24,000-a-year budget to buy and kit out second homes, they also killed off moves to subject their allowances to external audits following recent scandals.

But they did approve a new programme to get bigger and better constituency offices at an additional cost to the taxpayer of up to £3.2 million every year.

The package retaining the so-called "John Lewis list" of household items and property improvements was backed mainly by Labour MPs.

They included 33 ministers, among them Home Secretary Jacqui Smith, Culture Secretary Andy Burnham and housing minister Caroline Flint.

But more than half of MPs - including Prime Minister Gordon Brown and Chancellor Alistair Darling - stayed away from the Commons for the contentious vote.