US president Donald Trump’s new travel ban has been blocked by a federal judge in Hawaii, hours before it was due to come into force today.

US district judge Derrick Watson cited “questionable evidence” in the government’s argument that the ban was a matter of national security.

Hawaii is one of several US states trying to stop the travel ban with lawsuits.

Lawyers had argued that the ban would violate the US constitution by discriminating against people on the grounds of their national origin.

The state also said the ban would harm tourism and the ability to recruit foreign students and workers.

The Foreign and Commonwealth Office confirmed: “The introduction of temporary immigration measures on 16 March 2017 for nationals of Iran, Libya, Somalia, Sudan, Syria, and Yemen has been suspended following a federal court ruling.

“British passport holders weren’t affected by the measures but those who are either dual nationals with one of these countries or who have travelled to these countries since 2011 should note the unchanged rules for entry.”

President Trump described the ruling as “unprecedented judicial overreach”. The order would have placed a 90-day ban on people from six mainly Muslim nations and a 120-day ban on refugees.

Trump insists the move is to stop terrorists from entering the US but critics say it is discriminatory.

An earlier version of the executive order, issued in late January, sparked confusion and protests at airports, and was blocked by a judge in Seattle.

Trump said the ruling in Hawaii made the US “look weak”. He pledged to take the case “as far as it needs to go” including to the US Supreme Court, adding: “We’re going to win.”

Under the revised order, citizens of six countries on the original January 27 order – Iran, Libya, Syria, Somalia, Sudan and Yemen – would once more be subject to a 90-day travel ban.

Iraq was removed from the list because its government boosted visa screening and data sharing.