Rebels ambush Duncan Smith

Pressure from within mounts on Tory leader after Bercow quits

Iain Duncan Smith's authority as Tory leader suffered a severe blow last night after a shadow cabinet minister resigned and Michael Portillo led a Commons rebellion over gay and unmarried adoption.

John Bercow quit his post as shadow Work and Pensions Minister to join Labour, Liberal Democrat and some Conservative MPs in voting for a change in the law.

But it was Mr Portillo's intervention that stunned Westminster – the former defence secretary rallied MPs to defy Mr Duncan Smith's opposition to extending adoption rights beyond married couples.

In a direct challenge to the Tory leader's personal credibility, Mr Portillo, in effect, staged a parliamentary ambush that combined former cabinet ministers such as Kenneth Clarke with leading members of the Shadow Cabinet to undermine the leadership.

The show of defiance compounded Mr Duncan Smith's mounting troubles amid speculation that backbench MPs are plotting to oust him as early as next May.

In a carefully co-ordinated attack, Mr Portillo, who was defeated in the leadership race last year, widened his criticism beyond the issue of adoption to claim the Conservatives were "inconsistent" on social issues as a whole.

"They don't maintain a message about their belief that people should be free to lead their private lives on their own terms. They don't deliver a consistent message from one day to the next," he told BBC Radio 4's Start the Week.

Although he ruled out standing for the Tory leadership, Mr Portillo was clearly determined to exploit the biggest rebellion since Mr Duncan Smith defeated him. On a day of political drama, Mr Portillo used the House of Commons debate on the adoption Bill to throw back at Mr Duncan Smith the leader's recent conference pledge to support the vulnerable.

He said that it was time his party recognised the way "life in Britain is lived today and not how it was lived 20 years ago", as Mr Duncan Smith himself had said during the Bourne-mouth conference.

Mr Bercow made a biting speech, attacking the "prejudice" of his party and defending his decision to resign from the front bench on an issue of personal conscience. The Buckingham MP said that he had defied the Tory three-line whip because to do otherwise would be "a cop-out, a get-out, a sell-out".

He told MPs: "What we need in this debate is less prejudice and more fairness. We should aspire to govern Britain as she is, not Britain as she was..

Mr Bercow insisted that, despite his decision to step down on a point of principle, he still remained loyal to Mr Duncan Smith. He will continue to work as a "key campaign co-ordinator" for Mr Duncan Smith, and the Tory leader made clear that Mr Bercow's resignation would not bar him from returning to the front benches at a later date.

In his letter accepting Mr Bercow's resignation, the Tory leader said: "I am very keen that we make use of your flair and campaigning skills."

The policy split came after a week during which speculation has mounted over Mr Duncan Smith's future as party leader, with rumours spreading of growing disenchantment within the rank and file because of his approach.

Labour MPs have been given a free vote on the proposals on unmarried and gay couples, legislation that is back in front of the Commons after being rejected by peers.

But Mr Duncan Smith insists that such a reform would be against children's interests because unmarried couples are more likely to split up.

Andrew Lansley, the former shadow minister for the Cabinet Office and a long-term advocate of a liberalisation of the law, explained why he was going to vote against his party.

"The best Conservative tradition is focused on the here and now in which we live. Couples who are cohabiting do adopt, it is true not only of heterosexual couples but gay couples as well," he said.

Earlier, Mr Portillo highlighted speculation that he would only become Tory leader if offered the job unchal-lenged. "I do rule myself out, for two reasons in particular.

"One of those reasons is that I don't think I would ever convince the Conservative Party that I was the person to lead them, and the second is I don't think I would ever take the media with me," he said.

"Such is my history of different-shaped pigeon-holes that I'm not going to take the press with me and I think that's a very, very important consideration. Anyway, whatever the workings might be, my decision is clear." Oliver Heald was named as Mr Bercow's replacement last night. Mr Heald once held the post of junior social security minister under Peter Lilley in John Major's government.