Education is one of Britain’s most successful exports, bringing in almost £20bn a year. Universities and ministers love to talk up its economic benefits. They are less keen to discuss the costs and compromises incurred.

That makes a new report, on defending democracy in an age of autocracies, all the more important. The foreign affairs select committee found clear evidence that such states are seeking to shape the research agenda or curricula of UK universities and limit the activities of researchers. Witnesses said that, after contact from Chinese diplomats, one vice-chancellor asked a senior academic not to make political comments, and a pro-vice-chancellor cancelled a speaker. There is anecdotal evidence of Gulf states exerting similar pressure.

The central mission of universities is to educate and to understand the world better. Without freedom of expression, these dual foundations crumble. But commercialisation has made universities increasingly reliant on overseas sources of revenue, which provided a sixth of research income in 2017-18. Much international funding is appropriate. But donors usually want more than a plaque. In 2011 the director of the London School of Economics resigned over its acceptance of funding from sources linked to Muammar Gaddafi, the late Libyan dictator. It was reported that its plans for a China studies programme backed by a staunchly pro-Beijing venture capitalist were put on hold this autumn after outrage from academics. Overseas campuses – which have sprung up everywhere from China to Uzbekistan and Bahrain – are obviously vulnerable to pressure. So are students: last year, Saudi Arabia withdrew its scholarship programme for Canada, where thousands of its nationals were studying, after Ottawa urged it to release jailed women’s rights activists.

One obvious lesson is not to put too many eggs in one nation’s basket. (China provides more than a fifth of the UK’s 450,000 overseas students.) Another is to establish solidarity: a code of conduct is needed. At present universities seem to be in denial – the chair of one industry body told the committee that he had not heard one piece of evidence to substantiate claims of foreign influence. It should not be left to individual academics to uphold standards. Instead, institutions must be transparent about academic and financial relationships, and should document and publicly reject threats. They must also teach freedom of expression, not as an abstract ideal, but as the basis of life within the university – making it clear that disagreement is fine, but threats of any kind are not.

The report also urges the Foreign Office to broaden its focus beyond protecting universities from intellectual property theft and risks arising from joint research projects. That must be done quickly: Brexit will exacerbate the cash-hunger. The government should engage with Australia, Canada, New Zealand and the US, where there has been much closer attention to the issue. (At least 10 American universities have closed their Confucius Institutes, Beijing-funded language and cultural centres.) Unnecessary hostility to overseas students and partners is a danger of its own; racial profiling must be avoided and international collaboration can bring immense benefits. But it must be on the right terms – not those dictated in exchange for funding.