Crew union Nautilus International has warned about the effects on seafarers of US president Donald Trump’s travel ban.

General secretary Mark Dickinson has written to UK foreign secretary Boris Johnson, urging him to seek clarification on UK crew rights regarding shore leave, repatriation, transit and transfer in the US following the administration’s blocking of travel from seven mainly Muslim countries.

He expressed “deep concern” over the move and said he was “disturbed” at the implications.

“There