London: A Labour Party candidate for the upcoming British general election apologised after a Conservative lawmaker of Indian origin accused him of "racist" attacks and trolling her on Twitter, according to media reports.

John Clarke, who was chosen to contest from the Witham seat, emailed his Conservative Party rival Priti Patel last week after she complained about his behaviour to Labour Party leader Ed Miliband, reported Braintree and Witham Times on Tuesday.