Even as an ex-Cabinet minister declared the Government was "f****d", a poll showed Brown's personal rating plummeting from plus 48 last August to minus 37, a bigger drop than what his predecessor Neville Chamberlain experienced after he tried to appease Hitler in the 1930s. According to The Sun, the Financial Times poll does not see Brown steering the country through its current economic crisis.
Almost seven in ten Brits expressed "no confidence" - compared to 52 per cent of Germans, 51 per cent in the US and half in France.
Last night, Brown's supporters had to deny rumours that he had promised Schools Secretary Ed Balls that he would be the next premier. Balls also put out a statement denying he was running a secret leadership campaign.
Brown also faces backbench rebellions over plans to hold terror suspects for 42 days without trial and axing the 10p income tax rate.
Former Home Secretary Charles Clarke was said to be seeking candidates to challenge Brown for the leadership if the party slumps in next month's London mayor and local elections.
But Health Secretary Alan Johnson defended the PM and insisted he was a "serious man for serious times".
But Shadow Chancellor George Osborne said: "Gordon Brown has been found out. His economic reputation is in tatters."
The speculation comes as Brown flies to the US tomorrow for a four-day trip.