He told Holyrood magazine that the policy was "based on the sound socialist principle of redistribution".

Henry McLeish, former first minister, also told the magazine that he did not think Scottish universities could avoid charging higher fees.

But Scottish National Party MP Alex Salmond warned that Scotland could be "bounced" into accepting top-up fees.

He said: "I am against them in principle, but I am particularly against them because some people know that if they are forced through in England it will effectively bounce the Scottish Parliament - against its will - into introducing them in Scotland.

Vast majority

"That is why a vote for them south of the border is a betrayal of Scottish universities."

The comments came as a BBC poll showed the vast majority of Scottish MPs plan to vote on the issue in the Commons on 27 January.

The survey for Radio Scotland's Sunday Live programme received responses from 57 of the 60 Labour backbenchers and opposition MPs, 44 of whom said they would definitely vote.

Only one MP - Tory Peter Duncan - vowed not to vote on a point of principle.

Although some of the opposition to the policy is based on principle, many of the arguments used by the left are reactionary Sam Galbraith

Seven Labour MPs were among the 27 respondents who said they would vote against the proposals.

Six were undecided and 15 said they would support the government.

The 12 ministers and whips who were not polled are expected to vote with the government, giving the government at least 27 votes from Scottish MPs.

Mr Salmond said it was "extraordinary" that only seven Labour MPs were prepared to vote with the opposition on the issue.

And he said Mr Galbraith's comments showed that Labour had a "hidden agenda" to force top-up fees on the Scottish Parliament.

Moral superiority

The Scottish Executive has previously ruled out the introduction of tuition fees north of the border.

But, writing in the Holyrood magazine, Mr Galbraith said they could not be avoided.

"Top-up fees in Scotland are inevitable, so let's stop parading our false moral superiority and cease peddling the idea we are different in this country," he said.

Scots MPs to ignore Tory fees call

"Everyone agrees that our universities need more money and the only solution is for these institutions to charge students after they graduate."

He argued that Scottish universities would deteriorate if top-up fees were not introduced.

"Although some of the opposition to the policy is based on principle, many of the arguments used by the left are reactionary," he said.

"We need to throw off the shackles and dogma of the past.

"We need to learn that change is the servant of socialism rather than its enemy.

"Now is the time to restate our socialist principles. Top-up fees do that."

Poorer backgrounds

Mr McLeish said there needed to be a debate in Scotland about the best way to get more money for universities.

He said the executive should spend more on higher education, while also raising the question of whether variable fees were needed.

"We should examine it honestly, so long as there are safeguards in place to protect those from poorer backgrounds," he said.