Brown to unveil Labour's election slogan and key themes

Mr Brown will promise to "stand up for the many" at the launch

Prime Minister Gordon Brown will unveil the slogan of Labour's general election campaign in a speech at the weekend.

And the BBC has learned he will outline the four main themes he hopes will help Labour to a fourth term in government.

Mr Brown has not yet called the election but it is widely expected to be held on 6 May and all parties are stepping up their efforts.

Senior ministers Alistair Darling, Lord Mandelson, Alan Johnson and Yvette Cooper will be at Saturday's event.

The BBC has learned that the four themes to be outlined will be securing the economic recovery, protecting frontline services, protecting future jobs and industries, and "standing up for the many".

BBC chief political correspondent Laura Kuenssberg said the latter was a clear hint that Labour would direct some of its efforts at portraying the Conservatives as the party of privilege.

The themes also indicated Labour would seek to make the case that they could steer the economy back to sustained growth and restore the public finances.

Campaigning visits

Party members and other campaigners, including climate change activists, are being invited to attend the event, which is being held in the West Midlands.

It is clear that these meetings are simply designed to ship the cabinet into marginal seats to secure good PR for Labour's election campaign at taxpayers' expense Douglas Carswell Conservative MP

Other ministers will also take part in campaigning visits around the country on Saturday.

The full Labour manifesto will be launched at a later date.

A party source said last month that it would be the "most radical programme" offered "in recent times".

Last week, Conservative leader David Cameron also promised "radical" reform if his party wins the next election, declaring the Tories were back in the "centre ground" of UK politics.

And Liberal Democrat leader Nick Clegg has set out what he describes as the four "key principles" that will guide his party's campaign.

On Thursday, Mr Brown held a cabinet meeting in Durham - but was accused by one Tory backbencher of using taxpayer-funded trips for party political campaigning.

'Meeting activists'

Douglas Carswell wrote to the head of the Civil Service, Sir Gus O'Donnell, to complain and questioned whether deputy Labour leader Harriet Harman had breached ministerial rules.

It followed a previous cabinet meeting in Exeter - and reports have suggested that Ms Harman made plans to meet with party activists to discuss election strategy while in the area.

Ms Harman's office said all her visits complied with the ministerial code.

But Mr Carswell said: "It is clear that these meetings are simply designed to ship the cabinet into marginal seats to secure good PR for Labour's election campaign at taxpayers' expense."

An YouGov opinion poll for the Sun newspaper suggests that the Conservatives have a nine-point lead over Labour. It puts the Tories on 39%, Labour on 30% and the Liberal Democrats on 18%.

YouGov polled a UK representative sample of 2,145 UK residents on 16 and 17 February.