On Monday, he threatened to redirect $3bn in Harvard research funding to vocational schools. On Tuesday, the White House sent a letter to federal agencies, instructing them to review the approximately $100m in contracts the government has awarded Harvard and "find alternative vendors" where possible.

President Trump is trying to apply enough pressure to force the university to cave, while Harvard, a nearly 400-year-old institution, is aiming to play a long game against an aging president in his final term.