A senior member of Labour Party leader Jeremy Corbyn's team relinquished her role as home affairs spokeswoman on Wednesday, the final day of a British election campaign where she was ruthlessly criticised by rivals for being inept.

As home affairs spokeswoman, Diane Abbott was in line to become interior minister if Labour won Thursday, with responsibility for dealing with security and policing after recent terror attacks.

But a string of poor media appearances during the campaign, where she forgot key policy details, saw her pilloried in the media and targeted by Prime Minister Theresa May's Conservatives as one of Labour's weak spots.

When Abbott pulled out of two events on Tuesday, the Conservatives repeated that she was "unfit to serve as home secretary" and deal with the aftermath of the London and Manchester attacks.

Corbyn announced Wednesday that she had been replaced "for the period of her ill-health", adding that she had not been well for a "couple of days".

Abbott, the daughter of Jamaican immigrants, became the first black woman elected to the House of Commons when she entered parliament in 1987, representing the inner-city London seat of Hackney.

While the reputation of veteran socialist Corbyn has improved during the campaign, some Labour candidates had complained that Abbott remained a liability.

Labour's international trade spokesman Barry Gardiner said he had been told by party officials that she had a "long term" condition, which helped explain her performances in recent weeks.

Abbott's post will be filled by fellow London lawmaker Lyn Brown.