LONDON (AP) -- Here's a primer for the modern British politician: Smile a lot, give short, punchy answers to questions, mingle easily with the public, and always pretend to be enjoying it.
Or you can try it the Gordon Brown way.
The rumpled British prime minister rarely smiles, even though his handlers have tried to teach him how. He fills his speeches with obscure policy proposals, often appears uncomfortable with voters, and rarely seems happy.
And that was in the good old days, during his brief political honeymoon, before he had to deal with a global financial crisis and a simultaneous rebellion in his own Labour Party. His authority ebbing, his future at stake, he faces crunch time as the party's annual convention opens Saturday.
Brown's poll standing has gone from bad to horrendous, with the opposition Conservative Party enjoying its highest ratings since the glory days of Margaret Thatcher. Some Labour members are in open revolt, raising doubts about whether he can stay in power long enough to fight the next election, due in less than two years.
"He has been greatly damaged," acknowledges Paul Flynn, a Labour Party parliamentarian from Wales who believes Brown shouldn't be forced out right now. "He's at the very bottom of popularity. But he's dealing with an unprecedented world crisis, almost the collapse of capitalism, and he should do it without having to watch his back."
In British politics, unlike the U.S. presidential system, prime ministers must worry not only about being rejected by voters come election time; they can be ousted as party leader any time by their legislators and be replaced with a new prime minister.
That's how it ended for Tony Blair, who served 10 years before his party replaced him with Brown, and for Thatcher, the Conservative "Iron Lady," after her record 11 years in power.
Now, after little more than a year in office, Brown faces his own rebellion. It has spread to the junior ministerial ranks with the defection of David Cairns, a minister in the government's Scotland office who resigned and demanded an open contest for party leadership, a process that could end Brown's premiership.
The move has the support of a growing number of Labour Party lawmakers, but so far they don't have the 70 backers - out of 350 parliamentarians - needed to force a leadership election.
However, in British politics it's not enough for a party leader to outpoll his opponents - he has to crush them, or be seen as fatally weakened.
Some of the rebels are Blair loyalists still angry about what they see as Brown's plot to unseat Blair; others appear motivated by fear that under Brown's leadership they will lose their seats in the next election.
"They are getting nervous now because they can see they could all lose their seats in one night, which is what they saw happen to us," said Malcolm Rifkind, a former foreign secretary, referring to the resounding defeat of his Conservative Party by Blair in 1997.
That historic night ended nearly 18 years of Conservative rule that vanquished the once powerful trade unions and transformed the socialist economy. Rifkind believes that Labour is sputtering to a similar end, opening the road to another momentous change.
"The reason for Gordon's unpopularity are a combination of his personal style, which puts people off, combined with 10 years of a Labour government that seems to have run out of steam," Rifkind says.
When Brown came to power last summer he was riding high. As Blair's treasury chief he had managed a decade-long economic boom and shown a readiness to make tough, reform-minded decisions.
His first mistake, many analysts believe, was that he chose to serve out the remainder of Blair's term rather than put himself up for early election. He wavered with the opinion polls over this critical choice and was branded a ditherer.
Julia Clark, head of political research at the Ipso MORIS polling firm, says this decision was "the beginning of the end" of Brown's popularity because the public didn't believe his excuses for not facing the electorate.
She said he went on to be seen as mishandling the collapse of Northern Rock bank, the beginning of Britain's own version of the subprime mortgage crisis, and the government's loss of data files containing information about millions of Britons.
"The main thing is that Brown is seen to be a bit sneaky and a bit untrusting of his advisers and the public as a whole," Clark said. "He's lost our trust, and people are tired of Labour."
In some ways, the 57-year-old Scotsman is paying the price of not being Blair, who brought a fresh, youthful face to British politics, carved a role for himself on the world stage and introduced the idea that something new and exciting was happening, known as "Cool Britannia."
Now, with Labor more than 20 points behind the Tories, Brown's greatest asset - the economic boom of yesteryear - is being engulfed by the global market meltdown, and much is riding on whether his speech Tuesday to the convention can inspire new confidence.
"He has genuinely been buffeted by events, but in this crisis going on now, a leader would have risen to the occasion and gotten his message across," said George Jones, professor emeritus of government at the London School of Economics.
"But there's no coherent message coming from Brown so far. That's why his speech at the party conference is so important."