The man charged with murdering British lawmaker Jo Cox declared "death to traitors, freedom for Britain" when asked to give his name during his first court appearance.

Thomas Mair, 52, who lives in Cox’s northern England electoral district, was speaking Saturday in a London courtroom, according to the Press Association.

Coming within a week of the June 23 referendum on Britain’s membership in the European Union, Cox’s killing has the potential to lift support for remaining in the bloc, which had been flagging in the polls. Cox, 41, was a supporter of staying in the EU.

Campaign activities remained on hold Saturday. Prime Minister David Cameron is scheduled to appear on Sunday evening on a special edition of BBC Television’s "Question Time" show, following morning appearances by his pro-Brexit justice secretary, Michael Gove, and by Labour leader Jeremy Corbyn, who backs the "Remain" campaign, on the BBC’s "Andrew Marr" program.