Electoral chiefs, trade unions and political parties are gearing up for the possibility of a snap general election.

Speculation is intensifying that Gordon Brown will call an election next Tuesday following Monday's anticipated parliamentary statement on withdrawing troops from Iraq and a series of positive poll results.

The Mirror reported on Tuesday that the prime minister had met with top union leaders in a bid to secure £5m of funding.

The joint general secretaries of Unite, Tony Woodley and Derek Simpson, were called to Number 10 on Monday to discuss planning.

An email signed by both men and seen by the newspaper said: "As Labour's largest affiliate we must be in a position to play a leading role in re-electing Labour and defeating the Tories."

It also reveals the union's campaign will be run by its new political director Charlie Whelan - Brown's communications director when he was at Number 11.

Preparations

Meanwhile, officials in charge of organising elections have been preparing for a November poll.

John Turner, head of the Association of Electoral Administrators, held a meeting with officials at the Ministry of Justice on Monday to discuss ways of ensuring that voters not on the December 2006 electoral roll could register in time.

In a further sign that an election may be imminent, the Electoral Commission is sending out pre-election advice to returning officers.

The advice - which will cover the administration of elections including statutory timetabling for nominations and postal voting, and anti-fraud measures - is normally sent out when a general election is called. It will also cover the new constituency boundary arrangements.

But a spokesman for the Electoral Commission said that, given the unusual circumstances, it had decided to put the advice out immediately.

"It is our decision, but councils are now making contingency plans and we are helping them to do this," a commission spokesman told the Times newspaper.

Ministers also published draft orders naming returning officers in all constituencies, including those with new boundaries. Formal orders are expected to be laid this week.