What will life hold for Gordon Brown after No 10?

With the possibility of a deal between the Tories and Liberal Democrats ousting him from office, Gordon Brown now faces the same dilemma as Tony Blair did when he quit No 10 in 2007.

What to do next when you lose power in the prime of life, with years to go before retirement but no obvious career plan ahead of you?

Mr Brown's entire adult life has been dedicated to fighting his way to the top job in British politics, and after three years running the country from 10 Downing Street, he may struggle to adapt to life outside government.

In recent weeks, he has suggested that he might look for work in education or charity after leaving office.

But many observers believe he will find it difficult to wean himself off the adrenalin of power and the intellectual challenge of high-level decision-making and may seek a role in an international institution.

Speaking to GMTV's Lorraine Kelly just days before the General Election, Mr Brown said: "If I couldn't make a difference any more then I would go off and do something else. Sarah and I may go off and do charity voluntary work."

In what was seen by some observers as a veiled rebuke to Mr Blair for his money-spinning post-Downing Street corporate appointments, Mr Brown added: "I don't want to do business or anything else, I just want to do something good."

With his record of commitment to causes like alleviating child poverty, tackling climate change and ending global poverty, Mr Brown can expect to find charities queuing up for his service as patron, chairman or chief executive.

But the ex-Chancellor may have another escape route to hand, having been touted for years for a series of international finance posts.

He has been suggested in the past for the job of President of the World Bank, the international community's principal agency for channelling aid to developing nations.

The International Monetary Fund could also beckon. The global financial watchdog and lender of last resort might appeal to the man who has made speeches for years appealing for a new world financial architecture.

Even as he was coping with the banking meltdown, it was suggested Mr Brown could become the head of the new over-arching international regulator he believes should be set up to prevent another crash of the world's banking institutions.

And he has already taken on the job of co-chair of the United Nations' Advisory Group on Climate Change Financing, with a remit to secure money to help poorer countries adapt to global warming, though it is unclear whether he will have to quit this post on leaving Downing Street.

Life after No 10 could also see Mr Brown reversing the trend of City figures advising Government that he was so fond of, with his eventual appointment to a clutch of banking boards.

Another alternative would be to resume his academic career. Mr Brown was a university lecturer before he became an MP, having gone up to Edinburgh University at the age of 16, the youngest student there since 1945.

He would sometimes joke during prime ministerial speeches that his academic career spent in rigorous pursuit of the verifiable truth had equipped him for his life in politics.

Ensconced with his family in Kirkcaldy, Mr Brown could continue his career as an author of books on historical topics, with occasional forays across the Atlantic as a visiting lecturer to American institutions.