UK science minister Jo Johnson has resigned from his position as universities and science minister and as a member of the House of Commons, citing conflicts between what he thinks is best for the country and family ties.

Jo Johnson is the younger brother of Conservative Party leader and prime minister Boris Johnson, who has said that he will leave the European Union by an October deadline even if no deal is in place to regulate future relations with the bloc.

A no-deal Brexit is widely predicted to be detrimental to science . UK researchers have long worked closely with their counterparts in the rest of the European Union and easily travelled between countries. If no deal is reached and approved by Parliament, scientists in the UK would also be cut off from lucrative European research-funding programmes overnight.

James Wilsdon, a science-policy researcher at the University of Sheffield, says that scientists will be sad to see Jo Johnson go because he had a genuine understanding of the research sector and of the effects of a no-deal Brexit.

“Like the rest of the country, the science community’s concerns about Brexit are being discounted by those in charge, but it was helpful to have someone in the ministerial roles that understands what is at stake — and communicating that view to the heart of government,” he says.

In a tweet announcing his departure after nine years in office, Johnson wrote, in part: “In recent weeks I’ve been torn between family loyalty and the national interest — it's an unresolvable tension.”

Jo Johnson has covered various roles in previous governments, including universities and science minister under David Cameron and Theresa May. As part of May's government, he oversaw an ambitious shake-up of research funding.

In the run-up to the 2016 referendum, he campaigned against leaving the European Union, and this is the second time that he has resigned from the government over Brexit. In November 2018, he stood down from his position of transport minister in May’s government over the Brexit deal she had negotiated with the European Union — which was later turned down by Parliament. He rejoined the government, taking back the science and higher education brief, when his brother Boris Johnson became prime minister in July.

Jo Johnson's resignation comes as the UK experiences intense political drama. Boris Johnson lost his slim ruling majority in the House of Commons earlier this week, when several Conservative MPs defied the party line to vote for a motion that could result in legislation to stop the country crashing out of the EU without a deal. In response, the prime minister stripped dissenting MPs of their Conservative Party membership and called for a general election.