Gordon Brown has had "a good year" as Prime Minister and will win over voters, Health Secretary Alan Johnson insisted despite mounting woes for Labour.
As recriminations continued over the resignation of Scottish Labour leader Wendy Alexander, the PM came under fire from donors set to abandon the cash-strapped party.
Several went public to criticise his leadership in the wake of last week's humiliating fifth place in the Henley by-election, behind the Greens and the BNP.
Business guru Sir Gerry Robinson told the BBC Mr Brown was "showing all the signs of not being a capable leader" and had left the party in "probably an impossible position to come back from".
But Mr Johnson said Mr Brown was "well equipped" to run the country, adding: "In terms of what he is achieving, in very difficult circumstances, I think it has been a good year."
There was also some support from former London Mayor Ken Livingstone, who said the party had to "hang in there and deliver", not sack Mr Brown if it was to have any chance of a fourth term.
Refusing to blame the party for his defeat by Tory Boris Johnson in May, he backed the PM to steer the economy clear of recession but said he would not bet on a Labour general election win.
Sir Gerry, who gave Labour £70,000 between 2001 and 2005, said he would no longer be giving the party his financial backing.
"It is very straightforward. I think Labour are looking in a lot of trouble and I think Brown is showing all the signs of not being a capable leader," he told BBC1's Andrew Marr Show.
"Politics, like everything, is about leadership and leadership is about a capacity to make us feel we are doing the right thing at the right time and making everybody feel good - that the country's in good shape. If you haven't got that capacity then I wouldn't back it frankly, And I don't think Gordon has that capacity. It is a very, very difficult position to come back from. In fact, probably an impossible position to come back from."
