By politics.co.uk staff
The prime minister is the only one of the three main party leaders to improve their poll rating in recent months, according to ComRes.
Its poll for the Sunday Mirror and Independent on Sunday newspapers put David Cameron on 39%, compared to 38% in December and 37% in April.
That compares to just 21% thinking deputy prime minister Nick Clegg is a good leader of his party, down from 28% in January, and 22% thinking the same for Ed Miliband. He had rated 24% in April.
The boost for Mr Cameron is matched by an improvement in the Conservatives' polling position. They gained three points to reach 38%, just one point behind Labour who remained unchanged on 39%. The Liberal Democrats picked up a percentage point to move to 11%.
If these numbers were to be converted into parliamentary seats Labour would emerge with a majority of just eight seats.
There is a silver lining for the Lib Dems, however: 49% agreed that Mr Clegg deserved some credit for making the Tories think again on NHS reforms, compared to 26% disagreeing.
Fortty per cent agreed that the coalition had probably worked out better than just the Tories trying to go it alone, compared to 34% disagreeing - a five-point net swing towards the government.
The poll saw ComRes interview 2,004 British adults online on May 11th and 12th.