David Cameron had a difficult week - with over 100 of his own MPs rebelling over Europe - but he should listen to the wise advice of former Tory foreign secretary Geoffrey Howe, who savaged his approach to Europe in an article  for the Observer.
Given the other headlines - a new low for the PM as "loongate" dominates - the broadside from Lord Howe must almost have felt like light relief. But it comes from the man whose gentle but deadly attack on Margaret Thatcher's approach to Europe marked the point when she lost control of her own party.
Geoffrey Howe is right that the UK's EU membership is "a key point of leverage for this country in the modern world." He is also right to underline that the Conservative leadership is "running scared of its own backbenchers".
During a week in which David Cameron hoped for positive headlines about his visit to the United States, the Tory civil war on Europe at home left his leadership in tatters. It was ironic that while many in his party were calling for the UK to leave the EU, including two of his own cabinet ministers, he was discussing the great benefits of an EU-US free trade agreement with President Obama.
The joke in Westminster last week among Tory MPs was that they did not need to worry about acting against the leadership because it was only a matter of 24 or 48 hours before their position would become Conservative party policy. The rushed publication of a private member's bill order by the PM from across the Atlantic was designed to quash the Tory rebellion on the eurosceptic amendment lamenting the absence in the Queen's Speech of legislation for an in-out referendum. Yet 116 Tory MPs rebelled anyway, effectively declaring that they don't trust their party leader to deliver.
The last seven days are only the latest demonstration of what Howe aptly describes as the "ratchet-effect of Euroscepticism". Cameron thought that his promise in January to hold an in/out referendum at some point in the next four years would satisfy the eurosceptic beast in his party, but it hasn't.
The real lesson of the local elections, and of the UKIP surge, however, is that sections of the electorate are distrustful of mainstream politicians and are concerned above all about jobs, immigration and welfare. The disappointing and worrying unemployment figures published last Wednesday were drowned out by the Conservative row on Europe. The government needs to get a grip and focus on getting the economy on track.
Our EU membership is crucial to our future prosperity. As Howe underlines, given the UK's three per cent share of global GDP and one per cent share of the world's population, the UK's EU membership magnifies our voice in the world, economically and diplomatically.
The CBI's director general John Cridland was right to stress last week that leaving the EU would be bad for British business . Shrinking our domestic market from 500 to 60 million consumers simply does not make sense. The EU also gives us greater weight and bargaining power in free trade negotiations with big and emerging economies. Foreign direct investment, particularly in the automotive and aerospace industries, is attracted to our shores because we are a gateway to the world's largest single market.
The arrest of one of Britain's most wanted fugitives in Spain last week also served as a reminder that our EU membership is vital to the fight against organised crime and other challenges, like climate change, that are impossible for us to tackle alone.
Last week's chaos in the Conservative Party was a distraction from the real priorities for people across the country: jobs, growth and living standards. As Howe points out, it is the national interest, not party management or political advantage, which should guide decisions about our membership of the EU. Cameron has not only lost control of his party, he has also lost sight of the national interest. It falls to Labour to act responsibly, make a pragmatic and positive case for our continued EU membership and warn against the dangers of sleep-walking towards exit.