London - British Prime Minister Gordon Brown Wednesday dismissed growing unrest over his leadership within the ruling Labour Party by saying he was focusing on the bigger issues posed by the current economic challenges.

"What the prime minister is doing is focusing on the big issues facing the country and by far the biggest issue facing the country at the moment is the situation in the financial markets," his spokesman said.

The comment came after days of speculation that so-called Labour rebels would challenge Brown's leadership at the party's annual conference in Manchester next week.

But Labour's ruling body, the National Executive Committee (NEC), failed to support the move. Commentators have said any realistic challenge would require backing from within the cabinet, which has, so far not been forthcoming.

On Wednesday, Defence Secretary Des Browne warned the rebels to hold their fire, saying that there was currently "no alternative" to Brown, who took over as prime minister from Tony Blair in June, 2007.

As long as ministers were rallying around him, Brown's "mindset is to stay put," said one analyst.

Brown has been stung by public criticism of his alleged leadership weakness and indecision, culminating this week in a number of backbench Labour members of parliament (MPs) calling for a leadership contest.

On Tuesday, a former close ally of Brown, Scotland Secretary David Cairns, resigned from his post, saying he and a "number of ministers" were "uncomfortable" with the current situation.

It was "a matter of when, rather than if" there would be a move to force Brown out, he said.

Labour Party delegates will gather in Manchester from Saturday for their annual conference, certain to be overshadowed by the leadership issue and dominated by debates about the future direction of the party, which trails 20 per cent behind the Conservatives in the opinion polls. (dpa)