Prime Minister Gordon Brown gave one of the strongest indications yet on Tuesday that troubled bank Northern Rock could be nationalised before being privatised again at a later stage.

In an interview with ITV, Brown repeated a line put forward by his chancellor that all options for Northern Rock remained on the table, before adding:

"Because stability is the issue, we will look at every option and that includes taking the company into public ownership and then moving it later back into the private sector.

"So that is, yes, one of the options that has got to be considered."

Pressed about whether it wasn't now the only option for the bank, which has trouble borrowing money to finance its mortgage book as a result of the global credit crunch, Brown replied: "There are a number of companies in the financial private sector that have expressed an interest but public ownership - later to move it back into the private sector - is one of the options."

Earlier on Tuesday Chancellor Alistair Darling said a private sale remained the preferred option, although he didn't rule out the possibility of nationalisation.

The government has lined up respected executive Ron Sandler to run Northern Rock if the stricken bank is nationalised.

Brown, who spent 10 years as chancellor before taking over as prime minister last year, also told ITV he expected interest rates to come down during the year.

In rare, specific comments on monetary policy, particularly from the man who gave the Bank of England the independence to set interest rates without government intervention, Brown said: "I believe that even though this is a difficult time, people will see us taking the right decisions that will enable us to bring down interest rates at the end of this year, keep inflation low and therefore keep the economy moving forward even when in other countries the economy is stalling."