Elizabeth Truss has become the first cabinet member to endorse Boris Johnson in the Conservative leadership race.

Eastern Daily Press: Boris Johnson is currently facing court over accusations that he lied during the EU referendum campaign in 2016. Picture: Stefan Rousseau/PA WireBoris Johnson is currently facing court over accusations that he lied during the EU referendum campaign in 2016. Picture: Stefan Rousseau/PA Wire

The South West Norfolk MP announced in an interview with the Mail on Sunday that she would be backing Mr Johnson in the contest, which is due to kick off after Theresa May steps down as party leader on June 7.

Chief secretary to the Treasury Ms Truss is the first senior minister to publicly endorse former foreign secretary Mr Johnson - who, it was revealed on Wednesday, is facing court over misconduct allegations relating to the European referendum campaign in 2016.

In a piece for the Mail on Sunday Ms Truss announced she was joining Mr Johnson's team as his "policy tsar" and would be helping to devise his leadership manifesto.

She said the task of leaving the European Union, "deal or no deal", was not a task for the faint-hearted.

Eastern Daily Press: South West Norfolk MP Liz Truss at a railway summit. Picture: Ian BurtSouth West Norfolk MP Liz Truss at a railway summit. Picture: Ian Burt (Image: Archant)

"It will take bravery and a strong platform of policies that can deliver. Boris Johnson is the person with the credibility and oomph to lead at this crucial time and bring Britain with us," she said.

"Boris has proven he's a winner, and now we need someone to win the battle of ideas. He's on the side of the challenger, the start-up, the sole trader."

She called Mr Johnson a "British freedom fighter" who could "carry the Conservative torch to the next generation and win young people over".

She added that she and former Mayor of London Mr Johnson shared a "deep optimism about the power of individual creativity and enterprise".

Eastern Daily Press: Boris Johnson is one of 13 leadership candidates currently in the race to replace Theresa May. Picture: Gareth Fuller/PA WireBoris Johnson is one of 13 leadership candidates currently in the race to replace Theresa May. Picture: Gareth Fuller/PA Wire (Image: Archant)

Ms Truss' announcement comes a week after she ruled herself out of the leadership contest, which currently has 12 hopefuls on the bill including West Suffolk MP and health secretary Matt Hancock.

In an interview with the Sunday Telegraph last week she also said a Brexiteer was needed as the new Conservative leader - and while she did not pick a favourite she did say she would serve in a cabinet led by Mr Johnson.