Boris Johnson arrives at BBC studios to take part in a TV debate with candidates campaigning to replace British Prime Minister Theresa May, in London, Britain June 18, 2019. REUTERS/Peter Nicholls

LONDON (Reuters) - Boris Johnson, the frontrunner to be Britain’s next prime minister, apologised on Tuesday for any offence caused over his earlier comments, including those when he described Muslim women wearing burqas as looking like letter boxes.

“In so far as my words have given offence over the last 20 or 30 years when I’ve been a journalist and people have taken those words out of my articles and escalated them, of course I am sorry for the offence they have caused,” he said in a televised debate.