Speaking about Northern Rock, Mr Cable said: "We want to have maximum value for money for the taxpayer and we are not looking to a quick sale of the company."

But he warned against a restored Rock building society, saying: "How does the taxpayer get their money back? I mean it isn't actively being considered. There isn't kind of doctrinal problem. I was quite attracted to it."

A banking commission - set up the coalition - could influence the Rock's future, signalled Mr Cable.

He also declared the coalition was working well, insisting scepticism in sections of the Press did not correspond to the public mood.

"I get a sense, and the polls, tend to reinforce this that the public rather like the idea of two parties working together in the national interest.

"And internally, it works in a very good business like way," said the Business Secretary.
He said that contrasted with the previous Labour Government, with Lord Mandelson's autobiography showing its members "hated" each other.

While the coalition came from "different tribes", Mr Cable said: "Relations are very businesslike, good communication, a real sense of a team with a common objective and making serious progress delivering it.

"Of course there are people in both coalition parties who sound off from time to time, but that's what you would expect in democratic politics. But the coalition itself works cohesively and our parties are very much with us."

Asked if he planned to stay in the Cabinet for the coalition's planned five-year term, Mr Cable said: "That's my intention, yes."

But he added: "We don't to want to blur the identities [of the parties] and we actually think the idea of two parties working together is a good one. But we are not heading in a merger direction."

He insisted there was "no friction" over an immigration cap on people from outside the European Union (EU).

"The point I have been making, and very much with David Cameron's support, is that the way it is implemented has got to flexible. And it has got to take account of the needs of business", he said.

Mr Cable said companies like Nissan, for example, had to have flexibility to bring in senior managers and specialist staff while universities needed to be able to bring in top-class academies and students.

But he signalled he was ready to fight the Treasury over the scale of cuts, saying: "My department's concern is that we are able to continue to support growth.

"And I certainly want to emerge from this with a budget that enables us to do that in higher and further education, and science. But how we do it, we are still at very early discussions with the Treasury."