Salma Yaqoob, the former leader of the now defunct Respect party, has announced her intention to stand as Labour’s candidate for West Midlands mayor.

The leftwing activist decided at the 11th hour to apply for the nomination to challenge the current Conservative mayor, Andy Street.

Described in some quarters as an audacious bid, her rivals include the Birmingham Hodge Hill MP and frontrunner, Liam Byrne, and the Dudley councillor Peter Lowe, who is the unions’ favourite. The mayoral elections will take place next May.

Yaqoob, 48, a qualified psychotherapist, took her first steps into politics when she was racially abused after 9/11. Her initial involvement with the Stop the War coalition, then chaired by Jeremy Corbyn, led her to co-found the Respect party in 2004.

However, in 2012, Yaqoob quit as leader of the party after what she said had been an extremely difficult time and a breakdown in relations.

Since then the mother of three boys, who was born in Bradford but grew up in Alum Rock, Birmingham, has twice stood against the Birmingham Hall Green MP, Roger Godsiff, and in 2017 stood as an independent in Bradford.

She also received overtures from the Labour party. In the run-up to the 2010 general election Yaqoob was offered a choice of two traditional Labour strongholds, in Birmingham and the Black Country.

She rejected the bid, saying at the time: “I do not like mainstream politics which do not accurately reflect the concerns of many of the residents of inner-city Birmingham.”

But Yaqoob told the Guardian she had now found a home in the mainstream party as she believed it was finally standing for the “values it was created to uphold”.

She added: “I have stood for those values all my political life – equality, justice and peace. While New Labour championed wars abroad and privatisation at home, I could not support the party. I was never a member before and had no reason to join it.

“But with its unambiguous policies on equality, justice and peace it is offering a once in a generation opportunity to be a force for positive change for millions who have been ignored and left behind.

“The huge growth in party membership – making the Labour party the biggest political party in Europe – reflects that change and hope. And I’m proud to be part of that and champion it wholeheartedly.”

Yaqoob said her campaign would focus on improving public transport, reducing the impact of austerity cuts, bolstering affordable housing, and a bold new green deal.

“When it comes to the green agenda we need a major transformation. It does not have to be either or,” she said. “Under the new green deal I am proposing that we are at the forefront of the debate with new green technology and creating new jobs in the sector.

“I will use the strategic powers of the mayor to finally deliver for the many, not just the few.”

Yaqoob’s nomination is likely to ruffle a few feathers within Birmingham’s local Labour movement. Over the years, the Birmingham city councillor has come under fire from all sides. She has received death threats from extremist Islamist groups for engaging in western political life, and was pressured to apologise after refusing to stand in honour of a soldier injured in Afghanistan. She was also criticised for comments she made about the 7/7 bombings in London, which she says were taken out of context.

Yaqoob, named by Harper’s Bazaar as one of Britain’s most influential women, attributed the criticism to a sustained “smear campaign” against her because of her gender, race and outspoken political commentary.

“I have never, and will never, condone the actions of terrorists. There have been many occasions where my actions and comments have been deliberately misinterpreted for political gain by the opposition,” she said.

“I did not want the war and at the same time I condemn the actions of all terrorists. During these divided times we need a strong voice but sometimes there are forces at work who want to silence that voice.”