Education Secretary Alan Johnson, Justice Minister Harriet Harman, Development Secretary Hilary Benn, Party chairwoman Hazel Blears, Northern Ireland Secretary Peter Hain and backbencher Jon Cruddas are engaged in a closely fought tussle to become Gordon Brown's number two.

Appearing together for the first time before members of unions together in Bristol, each one set out their stall and stressed their commitment to traditional Labour values.

Mr Hain promised during his two-minute pitch that he would be a "campaigning" deputy and spoke of how he had fought the apartheid regime in South Africa during the 1970s. He also said the party needed to rebuild and listen more to what grass roots supporters wanted from the party.

Mrs Blears also spoke about her trade union past and stressed it was "essential" to maintain the party's traditional links with unions. "I believe the link between trade unions and Labour is essential. It gives us a hotline to workers at the sharp end."

Mr Benn, meanwhile, said he wanted a more "straightforward kind of politics" listening to people and "telling it like it is". He said he wanted "Labour movement values" to be at the heart of the government.

Mrs Harman told the audience of around 250 union members that the party needed to rebuild and face up to the criticism over the Iraq war. She also claimed she was the only candidate who could appeal to both the north and the south, and men and women.

Mr Johnson also discussed his close links to the trade union movement and how he had learnt politics from the grass roots. He pointed to the introduction of a minimum wage as one of the party's key successes.

The only backbench candidate, Mr Cruddas, meanwhile called for a new deal for working people and said he wanted to see greater protection for vulnerable workers.

The candidates faced a series of questions from union members on the floor on issues such as nuclear energy, education, the use of private contractors in the public service and housing.