Donald Trump attacked Britain’s revered public healthcare system on Monday in a tweet that prompted an angry response from UK politicians and the wider population. "The Democrats are pushing for Universal HealthCare while thousands of people are marching in the UK because their U system is going broke and not working," the US president wrote in an early morning tweet. "Dems want to greatly raise taxes for really bad and non-personal medical care. No thanks!" The tweet came after thousands of people marched through central London on Saturday in support of the National Health Service, which is straining under the weight of winter demand. It is the latest in a string of controversial tweets from Mr Trump invoking the UK, which have angered Britons and put some strain on the so-called “special relationship” between the two countries. In recent months, he has also made off-the-cuff remarks about terrorist attacks, shared anti-Muslim videos from a British fringe far-right group and cancelled a trip to open the new US embassy in London. Theresa May hit back at the tweet on Monday afternoon, with a spokesman from Number 10 saying the Prime Minister is "proud" of having a healthcare system which is free at the point of delivery. Health secretary Jeremy Hunt also criticised Mr Trump's comments, saying: "I may disagree with claims made on that march but not ONE of them wants to live in a system where 28m people have no cover. "NHS may have challenges but I’m proud to be from the country that invented universal coverage - where all get care no matter the size of their bank balance." The leader of the Labour party, Jeremy Corbyn, also chimed in, tweeting: "Wrong. People were marching because we love our NHS and hate what the Tories are doing to it. Healthcare is a human right." Meanwhile, Vince Cable, leader of the Liberal Democratic Party, told Sky News: “Give [Mr Trump] a good briefing on the health service”. “He obviously doesn’t understand it.” NHS staffing levels have been in crisis for months, an issue made worse by a winter flu outbreak. But despite its current woes, the NHS, which was created after World War II, is much loved among UK voters. It is widely regarded as central to the country’s political identity and promise of universal welfare, and protesters have been calling for more funds to support it. Unlike the insurance-led system in the US, healthcare is predominantly free at the point of treatment in the UK, and a pledge of more funding was viewed as a key reason for voters choosing Brexit in 2016. Mr Trump's own attempts to reverse his predecessor's healthcare reform, known as Obamacare, twice ended in failure, before his party succeeded in eliminating a key element - the so-called "individual mandate," as part of tax reform. The measure required individuals to buy coverage as a way to lower costs by ensuring that healthy people were part of insurance pools. It is not certain why Mr Trump chose to attack the NHS two days after the London protests. One possible explanation is an appearance by Brexit champion Nigel Farage, a personal friend of the president, on Fox News earlier on Monday in which he questioned the feasibility of universal healthcare and blamed the NHS's predicament on immigrants. Mr Trump’s comments on British issues have made him increasingly unpopular in the UK. An invitation from Prime Minister Theresa May for Mr Trump to visit Queen Elizabeth II has encountered growing opposition, fuelled in part by the president’s Twitter criticism of London Mayor Sadiq Khan in the wake of terrorist attacks last year. _______________ <strong>Read more:</strong> _______________ Mr Trump appeared to want to put things right when he met Mrs May in Davos last month. “We love your country,” Mr Trump said. “We have the same ideals and there’s nothing that would happen to you that we wouldn’t be there to fight for you.” However, as many Britons observed on Monday, his latest intervention into UK affairs is likely to call his much-delayed visit to the country further into doubt.