LONDON (Reuters) - Sabia Akram has spent most of her life campaigning for Britain's opposition Labour Party but she will not celebrate if it wins the July 4 election, having quit over leader Keir Starmer's handling of issues around the war in Gaza and race.

The Labour Party holds a commanding lead in opinion polls after Starmer steered it back to the centre ground following a trouncing at the 2019 election under his predecessor, veteran socialist Jeremy Corbyn.

But he has lost the support of some Black and Asian voters who traditionally vote Labour over his support for Israel and for only gradually shifting the party's position towards supporting a ceasefire in Gaza.

Labour's treatment of Diane Abbott, Britain's first Black woman lawmaker, and the blocking of a Muslim candidate have also alienated some voters, according to interviews with voters, a pollster, political activists and academics.

Starmer sought to move the party back to the centre ground, promoting candidates for the election who would vote as a disciplined bloc if they win, and that shift has alienated some ethnic minorities who backed Corbyn and his left-wing vision.

Sofia Collignon, associate professor at Queen Mary university, said while the party revamp was working nationally, it had caused strains among members and voters and Starmer's challenge was to hold all the different strands together.

Critics like Akram say he has sold Labour's "soul in order to seek the keys to No 10", the residence of British prime ministers.

"It's no longer defined by its values and its core principles," she said, adding that the party had become a home for whoever wanted to join, citing a right-wing lawmaker who defected from the ruling Conservatives.

A long-running Ipsos poll of ethnic minority voting intentions found that Starmer, in the second half of 2023, had the lowest net satisfaction rating of any Labour opposition leader since the series began in 1996.

With its 20-point lead in opinion polls, concerns among ethnic minorities may not affect the election result, Keiran Pedley at Ipsos said, but added: "If these trends are lasting - and we don't know if they will - then it's possible it could become more politically significant."

Akram, 43, resigned as a Labour councillor in Slough, west of London, in early June along with six others, citing what she saw as censorship around Gaza which meant she could not criticise Israel. She also cited the treatment of Faiza Shaheen, who was blocked from standing as a Labour candidate in a northeast London seat.

Shaheen said she had been told it was over historic tweets she liked which criticised Israeli supporters. She apologised but told the BBC she also thought it was because she was left-wing. She is standing as an independent.

The Labour Party did not respond to a Reuters request for comment about the allegations.

Last month Starmer, speaking after his party won a parliament seat in northern England and control of several councils across England, acknowledged Gaza had had an impact on Labour support in some areas.

BALANCING ACT

Akram also criticised the treatment of Abbott, a close Corbyn ally, who was suspended from Labour for over a year after she said Jewish, Irish and Traveller people did not face racism all their lives.

Media reports initially said she would be blocked from running in the election, sparking anger from some voters, before the party said she was welcome to stand as its candidate again.

Ngozi Fulani, founder and CEO of domestic abuse charity Sistah Space which is based in Abbott's neighbourhood of Hackney, said many Black people had wanted her to run as an independent.

"Most Black people have always voted Labour, that's my experience," she told Reuters. "(But) the Labour Party have been in decline ... we don't feel an association," she said, adding that Starmer's Labour didn't "take too much interest in matters that affect us specifically".

Hackney, a northeast London neighbourhood where 21% of the population is Black, is among the capital's most deprived areas, with more than one in three households living below the poverty line after housing costs are accounted for.

Of the 18 people Reuters interviewed there who have supported Abbott for nearly four decades, 14 said they thought she had been treated badly and that they would vote for her in the upcoming election following her reinstatement.

Starmer, the country's former chief prosecutor, became Labour leader in April 2020, vowing reform after the equalities watchdog said the party had discriminated against Jews.

A 2022 independent investigation also found structural racism, sexism and factionalism in the party, and a "hierarchy of racism" where tackling antisemitism was the priority.

Labour has long been the political home of many ethnic minority voters and according to British Future, a think tank, one in five of its election candidates are from an ethnic minority background. The last census in 2021 said 18% of the population in England and Wales were ethnic minorities.

However, other parties - including Prime Minister Rishi Sunak's Conservatives - have more visible representation in government and party structures than Labour, which might incline voters towards them more in future.

(Editing by Emelia Sithole-Matarise)

By Suban Abdulla and Ben Makori