Chancellor Alistair Darling is to outline the government's stance on the possible sale of Northern Rock.
Northern Rock has said that proposals it has received so far from potential investors were "materially below" the stricken bank's share price.
The government has given the bank emergency funding amid fears potential private buyers could need more loans.
Two suitors, Virgin Group and Olivant Advisers, have both submitted their proposals to rescue the bank.
The bank's shares collapsed after it was forced to seek emergency funding from the Bank of England in September.
The bank said that it expected further expressions of interest to emerge.
Two suitors, Virgin Group and investment firm Olivant Advisers, have both submitted their proposals to rescue the bank.
Separately, the government has said there was no certainty that any bidder for the Rock would have access to Treasury-backed loans after February.
Mr Darling is due to unveil a "statement of principles" to MPs that will guide the government's approach to Northern Rock, the Treasury said.
Chancellor Alistair Darling has outlined the government's stance on the possible sale of Northern Rock.
But a binding offer is seen as unlikely to emerge until the Treasury makes clear whether it will extend its £24bn credit lifeline beyond February, when the emergency funding is due to be withdrawn.
Northern Rock said that while it would still analyse and discuss proposals it had trecoieved, "the value to shareholders from any of the proposals remains highly uncertain".
Assurances sought
They would depend on factors including an improvement in market conditions including access to liquidity, it said.
BBC political correspondent Norman Smith says no option has been ruled in or out by the Treasury, which will not say whether it wants the bank sold, whether it will provide more money, or whether taxpayers will get all their money back.
Northern Rock still has around £100bn worth of assets, our correspondent added.
The Liberal Democrats have renewed their call for the bank to be nationalised, stabilised and then sold off, because they say the directors and shareholders have no interest in safeguarding taxpayers' money.
The Tories are also demanding assurances taxpayers' money is being safeguarded.
Reports suggest Treasury advisers were working on plans to extend the bank's emergency funding.
The government has a number of options when it comes to Northern Rock's future - it could let the bank go into receivership, seek a private buyer, or take it over itself.
Shareholder objections
The Treasury has dismissed the idea of the government taking control of the bank at this stage.
Meanwhile, Northern Rock's biggest shareholders are reported to have said the sale of the bank should be stopped.
RAB Capital and SRM Global, two hedge funds that own for 13% of the bank's shares, argue that forcing a quick sale or break up of the bank would allow Northern Rock to be bought on the cheap.
Northern Rock has already announced its chief executive, Adam Applegarth, is to step down in the New Year, and that four non-executive directors were to resign immediately.
At the same time, four board directors stood down from the board but have remained with the firm.
