Ecuador’s decision to grant asylum to WikiLeaks founder Julian Assange puts Britain in uncharted diplomatic and legal waters, as it insisted yesterday it would go ahead with extraditing him to Sweden.

When Foreign Minister Ricardo Patino announced that Ecuador was giving the 41-year-old Australian political asylum, it raised a host of questions.

London reacted by insisting that, effectively, the decision from Quito changed nothing and that it intended to go ahead with extraditing Mr Assange to Sweden as it is required to do under the European arrest warrant. Put simply, the problem for Mr Assange and supporters is how to get him out of the embassy and on to a plane.

For now, it appears that Mr Assange has no option but to bed down for a long stretch in the Victorian redbrick building near the famed Harrods department store.

Britain’s foreign minister William Hague admitted that the standoff could drag on for years. “It is a difficulty for Ecuador and for Mr Assange but this is a strange position for an embassy to be in.”

Mr Hague said that “diplomatic immunity exists to allow embassies and diplomats to exercise proper diplomatic functions. The harbouring of alleged criminals, or frustrating the due legal process in a country, is not a permitted function.”

Lord Alex Carlile, from the coalition Liberal Democrat party, said Britain must now be patient.

“He has nowhere to go and when he does eventually emerge he will be arrested and extradited to Sweden,” he said.

He warned that if Britain stormed the embassy to remove Mr Assange it could set a dangerous precedent for British embassies and diplomatic missions abroad.

Speaking shortly after Mr Assange took shelter in the embassy in June, Paul Whiteway, London director of the Independent Diplomat consultancy, said he could be arrested even before leaving the building.