Sir Richard Branson's Virgin Group yesterday confirmed it will lodge its bid for troubled bank Northern Rock on Monday.

The Virgin consortium said it was hammering out the final details of its offer for the crisis-hit lender in time for the February 4 deadline.

Chancellor Alistair Darling gave Northern Rock's suitors until next week to come up with their definitive offers after announcing a financial package to smooth the path for a private sector sale earlier this month.

The news comes as reports suggest the plans announced last week to sell Government-guaranteed bonds to pay off Northern Rock's £24 billion debts failed to flush out new bidders.

No new potential rescuer has entered the fray, it has been claimed.

There are believed to be only three contenders to rescue the stricken Newcastle lender - the Virgin team, investment group Olivant and the bank's own management.

But it is thought Northern Rock bosses, who are putting together proposals for a "self-help" option, are struggling to raise the necessary capital.

It is suggested the board's plans for an internal solution would see Northern Rock scaled down so it could be run as a smaller company, although the plan is said to rely on a rights issue.

Northern Rock declined to comment on its proposal ahead of the deadline.

Olivant also remained tight-lipped on its plans, although it is believed the group - headed by former Abbey chief Luqman Arnold - is also intending to meet the Monday deadline.

Virgin's plans unveiled so far would see Northern Rock rolled into its financial services operation Virgin Money and rebranded.

If successful, the consortium plans to inject £1.3 billion of new equity into the bank, with half the money coming from the itself and the remainder raised through an offer to existing Rock shareholders to buy new shares for 25p each.

The group plans to take no more than 55 per cent of the company once the transaction has been concluded.

But it is understood that it may be working on a sweetened final offer that would make it more palatable for shareholders.

Olivant, meanwhile, aims instead to parachute in a management team led by Mr Arnold as chairman to begin an immediate turnaround of the business, keeping the Northern Rock brand and business intact. ..SUPL: