The pro-EU chief of one of the UK's largest and most influential trade unions has been accused of sexism after he reportedly verbally attacked Conservative minister Priti Patel. Tim Roache, the general secretary of the 625,000 member-strong GMB union, apparently told the union's annual conference in Brighton on 6 June: "Priti Patel, surely a contradiction in her name."

The remarks were covered by journalist Kevin Maguire, the associate editor of left-wing tabloid The Daily Mirror. James Cleverly, a Conservative colleague of Patel's and fellow Vote Leave campaigner, reacted to the comments by rhetorically asking his Twitter followers: "Sexist, racist, blind or all three?"

Britain Stronger in Europe, the lead Remain campaign, has since distanced itself from Roache.

A spokesman for the pro-EU campaign said: "You can disagree as much as you like with Priti Patel and Vote Leave's plan to wreck our economy but this kind of personal attack has no place in this campaign and it distracts from the vital decision facing the British public on the 23 June."

The comments could also prove embarrassing for Labour, which has strong links with Britain's trade unions. Harriet Harman, the party's former interim leader, has previously warned that women have been excluded from the EU referendum debate.

"Half the population of this country are women and our membership of the EU is important to women's lives. Yet men are – as usual – pushing women out," she said in May. The UK's largest trade unions, including Unison and Unite, are backing a Remain vote at the referendum. But rail unions Aslef and RMT are campaigning for a Brexit. The GMB union had not responded to a request for comment at the time of publication.

Jeremy Corbyn and Tim Roache
Labour leader Jeremy Corbyn [L] and GMB Union general secretary Tim Roache [R]Getty