DAVID Cameron has broken his 24-hour silence on the White Paper by claiming it left a "huge set" of unanswered questions.

The Prime Minister yesterday said that pertinent arguments over independence showed that Scotland was better off staying part of the United Kingdom.

It came as the Nationalists accused him of being "a pathetic big feartie" by not agreeing to a head-to-head debate with Alex Salmond.

Meantime, in the House of Lords, which, like the House of Commons, received just a single copy of the Scottish Government's White Paper, Lord Foulkes called for ministerial statements and day-long debates, warning peers that non-engagement would mean "sleepwalking into the break-up of the United Kingdom".

During Prime Minister's Questions, Scottish Labour's Anas Sarwar branded the Nationalists' prospectus a "thick document full of false promises", whichwas nothing more than a wish-list.

Mr Cameron agreed, telling MPs, accompanied by heckling from the SNP benches: "We have been waiting a long time for this document. We were told it would answer every question and yet no answer on the currency, no answer on the issue of EU membership, no proper answers on Nato.

"We were just left a huge set of questions. And, frankly, for Scottish people the prospect of a £1000 bill as the price of separation."

Later, Pete Wishart, the SNP MP for Perth, noted how the PM had vowed to fight for the Union with his head, heart and soul but said when it came to a debate "some guts are needed". He urged him to "stop being a pathetic big feartie" and debate with the First Minister.

To more heckling from Nationalists, Mr Cameron said there should be televised debates but these should be between the leaders of the respective campaigns. He told Mr Wishart: "I know you want to find every sort of distraction possible because when it comes to the economy, when it comes to jobs, when it comes to Europe, all the arguments are for staying together."

John Bercow, the Speaker, interjected, and addressing Mr Wishart's Nationalist colleague, Angus MacNeil, said: "For future reference Mr MacNeil, you shouldn't be yapping at the Prime Minister like an over-excited puppy dog. It's unseemly. You can do a lot better if you try."