Commons leader Harriet Harman yesterday denied reports of a rift between her and the Prime Minister over a bid by MPs to change the abortion laws.

Ms Harman told MPs there was no truth in a newspaper claim that she had clashed with Gordon Brown over the amount of time to be allowed to debate the Human Fertilisation and Embryology Bill next week.

Ms Harman said she would "do her best" to allow as much time for debate as possible.

A cross-party group of MPs will table an amendment in a bid to allow women to have an abortion on the NHS in Northern Ireland, a right they do not have, but any such move would be opposed by the political parties there. The DUP's Nigel Dodds has said the parties are "united" in opposing any relaxation of the law.

At questions on Commons business yesterday, MPs expressed fears that the government would try to use parliamentary procedures to prevent them debating changes to the law.

The Tories and Liberal Democrats both called for reassurances the government would not try to limit debate.

Shadow leader of the House Theresa May said: "There are reports today that you and the Prime Minister have fallen out over the amount of time that should be allowed for this debate. Will you confirm you will be making every effort to ensure that there will indeed be a full debate for the remaining stages of that bill?"

Ms Harman replied: "There is no truth in the report that you referred to." She added: "There is going to be a further, what I hope will be a full, day of debate."