Bercow tells MPs to make less noise and stop spinning

But less than 48 hours into the job, he was branded "divisive" by a shadow Cabinet member and criticised by a senior Labour MP.

After the ousting of former speaker Michael Martin, Mr Bercow, 46, faces a battle to restore the reputation of the post of Speaker.

In a brief statement to MPs, he laid out three rules he expects to be followed. He called for less noise from MPs when colleagues are speaking in the House in order to maintain "an atmosphere of calm, reasoned debate".

Ministers should also make policy statements to Parliament first and they should not be released through the media beforehand.

He also demanded that ministers stick to allocated time for statements and give responses of a reasonable length, and that backbenchers should only ask one supplementary question.

He singled out Commons leader Harriet Harman on the issue of ministers telling the House first about major statements.

Mr Bercow also hinted that ministers in the Lords, such as Business Secretary Lord Mandelson, could be required to give statements to MPs in the Commons. He said it would require a change in the rules but it was an issue the Commons procedure committee "might wish to consider".

But his authority was already under threat after shadow defence secretary Liam Fox said he believed Mr Bercow, who is despised by many Tories, to be the wrong man to be Speaker.

"I think to have a Speaker who is regarded as divisive is the worst possible option," Mr Fox told his local paper the Clevedon Mercury. The shadow Cabinet member insisted that this conversation had been off-the-record but did not deny the quote.

Labour MP Frank Field, who quit the race to be the next Speaker, said it was "troubling" that Mr Bercow had not made more in his acceptance speech of his plans to reform the Commons.

"Prime Ministers and Speakers are never more powerful than at the point of election. Any reforming Speaker is going to face huge resistance here in the Commons," he said. "That is why I was disappointed that the acceptance speech was not mainly devoted to outlining the changes the Speaker intended to bring in immediately."

Shadow Commons leader Alan Duncan yesterday described Mr Bercow as a "motivated and complex character", adding: "I think that a lot of people are annoyed that he worked out how to get elected and got there."

Mr Bercow was elected Speaker on Monday after winning the backing of 322 MPs, beating Tory grandee Sir George Young who got 271 votes.

However, many Tory MPs regard his election as a Labour stitch-up to avenge the toppling of Mr Martin who was the first Speaker to be forced out for more than 300 years.

Mr Bercow has promised reforms to Parliament. He is moving his young family into Speaker's House, and has chosen to wear in the chair a plain business suit and tie, with an academic gown, ditching the traditional white tie, wig and buckled shoes.