The battle to become Birmingham’s first directly-elected mayor has been blown wide open with the announcement by former Cabinet Minister Liam Byrne that he wants the job - and he has listed his top three priorities as "jobs, jobs and jobs".

The MP for Birmingham Hodge Hill is a key member of Labour leader Ed Miliband’s shadow cabinet team at Westminster, and has been leading the policy review that will help decide his party’s manifesto at the next general election.

But he has announced plans to leave his high-profile national role behind and dedicate himself to running Birmingham – if the city votes “yes” in a referendum on creating a mayor, on May 3.

Mr Byrne announced his priorities would be “jobs, jobs, jobs” – and he would get to work encouraging major firms to invest in Birmingham on his first day in the new role.

He also revealed that, in a major coup, he had already won the support of former city council leader Sir Albert Bore, the leader of the Labour group on the city council.

Sir Albert had previously hoped to stand for mayor himself, but will now back Mr Byrne – and would serve as Deputy Mayor in any administration led by the MP.

However, even if the city does choose to create a mayor, Mr Byrne still needs to defeat Labour rivals Sion Simon, the former MP for Erdington, and Gisela Stuart, the MP for Edgbaston, in the battle to become the party’s candidate.

If he was selected, he would need to stand down as MP for Hodge Hill, prompting a by-election in the Birmingham constituency which would probably take place on the same day as the mayoral election, on November 15.

His announcement will be seized on by critics of Labour leader Ed Miliband as showing a lack of confidence in Labour’s prospects nationally.

But Mr Byrne insisted he backed Mr Miliband, and said he received his party leader’s blessing to stand for mayor of Birmingham when the pair met on Sunday.

Speaking to the Mail, he said: “If the city votes ‘yes’ for a mayor then I’m going to seek to be Labour’s candidate.

“I’m standing because I’m passionate about our city. It’s my home, it’s where my children will grow up, and I think our best days are ahead of us.

“But the truth is the city is now at a fork in the road. Unless we get some big issues sorted out now then we’re not going to be the city I know we can be in the years to come.

“That’s why I think the city needs to vote yes to a mayor. Only a city can bring together people in the way we need, to get these issues sorted.”

Creating jobs in Birmingham would be his top priority as mayor, he said.

“Unless the city comes together to get people back to work then Birmingham is not going to be the city I know it can be in the years to come.

“Right now there are only 6,500 vacancies in the job centres – but there are 52,000 people on the dole.

“And we are going to need to create more jobs for the years to come. So jobs will be number one, two and three issue for me.

“And there are big things a mayor can do very quickly, starting with inward investment. If you look at Telford or Warwickshire or Solihull, they have done far better at bringing in inward investment.

“I know the investment is there.

“The first thing I would do on day one is ring up the leaders of major businesses in Britain and abroad and say, what is it we need to do as a city to bring your businesses and new jobs here to Birmingham?”

He also wanted to boost small businesses by ensuring the city council and other public bodies supported local firms, he said.

“Small businesses create half of new jobs. That’s why a mayor needs to bring together the public sector in Birmingham and say look, all things being equal we need to buy Birmingham first.”

His career in Government, which included roles as the minister for immigration, second-in-command at the Treasury, Cabinet Office Minister and Minister for the West Midlands, would help him represent Birmingham on the national stage, he said.

“The mayor has to know how to get Whitehall working for Birmingham.”

He welcome the announcement from David Cameron, that city mayors would be invited to London for a “cabinet of mayors”, chaired by the Prime Minister, where they would be able to tell government directly what the cities needed.

“I know my way around Whitehall and how to get things out of Whitehall, and that is one of the first things I will do if I’m lucky enough to win the Labour selection.

“Albert Bore and I will seek to see the Prime Minister quickly to say, here is the list of powers we think a mayor will need.”

Mr Byrne said he planned to run what he called a “joint administration” with Sir Albert if elected mayor.

He said “I think we’d be a hell of a double act.”