The House wants to ban new government-funded plans from covering abortion at all, while the Senate will require patients pay separate premiums with their own money for abortion as a supplemental benefit.

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But speaking on BBC Radio 4's Today programme, Home Secretary Theresa May said the government was "right" to take the position it had, reiterating there were "no plans to reduce the abortion limit".

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"The Pennsylvania legislature could have rationally believed that some married women are initially inclined to obtain an abortion without their husbands' knowledge because of perceived problems -- such as economic constraints, future plans, or the husbands' previously expressed opposition -- that may be obviated by discussion prior to the abortion, " wrote Alito.

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One MP who will be poised to pounce is the Conservative Nadine Dorries - she plans to put down an amendment to guarantee that a woman considering abortion has access to non-compulsory counselling and advice from someone who has no financial interest in the outcome of her decision.

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Prime Minister David Cameron insisted, however, that the government at Westminster had "no plans" to bring in new laws governing when a women could legally have an abortion.

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