Tory pledge to limit votes by Scots MPs

The Conservative leader will promise the constitutional changes in the run-up to the next election, the Daily Mail can reveal.

If his plans were realised, Gordon Brown and others representing constituencies north of the border would be denied a say on legislation covering areas such as English schools and hospitals.

Senior Tories believe the policy announcement will embarrass the Chancellor, expected to become prime minister next month, by focusing attention on the growing influence of Scottish MPs.

Polls suggest English voters are increasingly concerned that devolution of power means Scottish MPs are able to vote on issues that affect only England. English MPs are unable to vote on the same issues in Scotland.

The constitutional dilemma is known as the "West Lothian question".

Mr Cameron's solution has been secretly drawn up by the former Scottish Secretary, Sir Malcolm Rifkind. It is being called the "East Lothian answer" as Sir Malcolm lives there.

The solution would not involve a separate English Parliament, which critics fear could lead to the break-up of the UK.

Instead, there would be a "grand committee" of all English MPs.

This committee would be convened at Westminster whenever Parliament is considering legislation deemed by the Speaker of the Commons to apply only to English constituencies.

Similar conventions already define the relationship between the House of Lords and the Commons, with peers having agreed not to reverse decisions of MPs in certain circumstances.

The revival of the Northern Ireland assembly means that Ulster MPs would also be excluded from the committee.

So would Welsh MPs if, as expected, Wales gets a proper law-making body which is able to pass primary legislation.

Labour has repeatedly dismissed calls for "English votes for English laws" on the grounds that it will create two classes of MP, with Scottish MPs relegated on many issues.

The Tories will argue that their proposal ensures all MPs remain equal. They would retain the same formal and legal powers when the Commons meets as a whole.

A source close to the plans said: "The practical consequence will be that England enjoys a measure of devolution comparable to that of Scotland, Wales and Northern Ireland.

"It's completely unfair for the English to become the only people in the UK who don't have a final say on new laws affecting only their part of the union."

It now takes only a small number of English Labour MPs to rebel for Labour's "tartan army" of Scottish MPs to become crucial.

The party's majority in England was slashed from 117 to 43 in last year's General Election. This means that if only 22 Labour MPs in England oppose a Government measure, the votes of traditionally-loyal Scottish members become critical.

Labour has already relied on Scottish votes to pass contentious legislation which only applies in England, including two votes on foundation hospitals and two on university tuition fees.

On tuition fees, Scots MPs who backed Government legislation were accused of hypocrisy as the Scottish parliament, established in 1998, had ruled them out there.

The West Lothian question was first posed by Labour MP Tam Dalyell, in the 1970s. He warned that the creation of a Scottish parliament would create a serious constitutional anomaly.

The Tories' focus on the issue will be unwelcome to the Chancellor, who at the weekend, denied that being a Scot was a "problem" for his campaign to become prime minister.

He said: "I am very proud of my Scottishness. I am proud also that I am a citizen of Britain."

Allies of Mr Brown point out that John Major relied on the votes of Ulster Unionist MPs after losing his Commons majority.