Edinburgh and London should publish their "red lines" for independence talks before next year's referendum, according to a report by the Lords Economic Affairs Committee.

Both sides, led by Alex Salmond and David Cameron, should clearly state non-negotiable positions on issues including defence, currency and the national debt, according to the report published today, which also warns the talks could take years and advises against "sleepwalking" into independence.

Danny Alexander, the Chief Secretary to the Treasury, has already dismissed the call, saying the UK Government would not enter any pre-negotiations.

A Scottish Government spokesman said its position on "all these issues will be set out before and in the White Paper – and that is what the people of Scotland will be voting on".

The report refers to a "conspiracy of silence" the committee said was "inhibiting open debate" in Scotland.

The peers have also criticised the Scottish Government's claims an independent Scotland would have influence over the Bank of England as "entirely fanciful".

They said Alex Salmond's hope that the central bank will also act as a lender of last resort is "implausible"; that European Union membership would not be automatic; and that the cost of re-applying to join the EU could be the adoption of the euro.

Their report also warns that, if future liabilities such as public sector pensions are included, Scotland's national debt would be £93 billion – or 123% of GDP, although that would still be smaller than the UK's current ratio of 147%.

Ahead of the publication of the report, the cross-party committee defended itself against accusations it was biased and insisted it had taken no view on the independence question.

Chairman Lord MacGregor said his committee contained no nationalist members because there were no SNP peers, adding: "We have bent over backwards to be dispassionate about the issues".

John Swinney, the Scottish Finance Secretary, said: "It will be no surprise to people across Scotland that out-of-touch unelected lords think Scotland is too small and too poor. Westminster has been peddling this nonsense for decades.

"All the evidence, including in this report, shows Scotland is in a far stronger financial position than the UK as a whole.

"Retaining sterling as Scotland's currency within a formal monetary union is a proposal endorsed by the leading and nobel-prizewinning impartial economists of the Fiscal Commission, who advise governments and economic institutions around the world, and who are very clear this is in the UK's best interests as well as Scotland's."

He also described evidence heard by the committee, that independence could cost 25,000 defence jobs as "ridiculous".

Mr Alexander said: "We have been clear we will not 'pre- negotiate' the terms of independence before people in Scotland have had their say in the referendum.

"To do so would require the Government to act on behalf of only part of the UK."