Labour's hopes of a summer fightback fuelled by Tory infighting over the NHS appear to have been dashed.
An ICM poll published in The Guardian gave the Conservatives a commanding 16-point lead over Labour.
And the survey - carried out since Tory MEP Daniel Hannan's attack on the NHS on US television - showed little damage had been done to David Cameron's party as a result of the row.
The Tory leader was forced to slap down the high-profile MEP over his comments that the NHS was a "60-year mistake".
Some 48% of those surveyed think healthcare would be better under a Tory government, with 41% appearing to agree with Labour warnings that it would be worse.
Worryingly for Mr Brown, 24% of current Labour voters think the Tories would improve the NHS.
The poll put Conservative support at 41%, unchanged since last month's poll for The Guardian but down two points on a more recent ICM survey for the Sunday Mirror.
Labour support has dropped two points to 25% since July and one point since the more recent poll.
The Liberal Democrats are on 19%, down one since July but unchanged since the later poll.
