A new report has called for an overhaul of our relationship with Europe. If David Cameron doesn't negotiate major changes to everything from employment rules to banking regulations, the authors suggest he ought to lead the UK out of the EC.
The study, called Change or Go, says that the areas for reform that Cameron has outlined so far - focusing on allowing the UK to change its welfare rules - don't go far enough. It sets out ten reforms it wants to see before the referendum on Europe in 2017.
These include the reintroduction of a national veto - to block any laws the UK fundamentally disagrees with. It also calls for action to give the UK control of its own social and employment laws, and control its own migration policy.
The EU should also exempt Britain from its stated aim of 'ever closer union', and introduce a mechanism for protecting non-Eurozone states.
It should force the EU to reduce the burden of regulation on business, and reverse 'damaging' financial laws. In addition, it needs to show it is capable of securing comprehensive free trade deals with other countries.
It also wants to see the EU budget cut for good and new laws forcing the budget to be transparent.
If Cameron doesn't secure these changes, Business for Britain - the group behind the report - wants to see the UK leave Europe. It argues that there are few good reasons to stay anyway, because less than 5% of companies export directly to the EU, whereas 100% of them are forced to sign up to the restrictions imposed as part of being a member.
It also shares its belief that EU countries are not the kinds of powerhouses we want to link our economic future to - as Europe's share of global GDP drops, and its population ages. It argues that the UK is big enough, and attractive enough to global partners in its own right, to thrive outside the EU.
The group boasts an enormous number of high profile business leaders, including Lord Bell (chairman of BPP Communications), Lord Bilimoria (Chairman of Cobra Beer Partnership), Roger Bootle (Managing Director of Capital Economics), and a number of fund managers including Helena Morrisey and Alexander Darwall.
However, it's worth pointing out that Business for Britain is an unashamedly Eurosceptic group, ideologically opposed to Britain's involvement in the EU. The fact that they have come out so ardently in favour of enormous change or leaving the EU, should come as no surprise at all.
There remain large numbers of business leaders and experts who warn that leaving the EU would be incredibly damaging - including John Allan, the chairman of Tesco, who has warned that it would be relatively simple for major businesses to simply move their headquarters out of London and into another European city.
But what do you think? Are you happy in the EU, or do you think we ought to get out? Let is know in the comments.
We need massive change in Europe - or to leave - say business leaders
John Boot opened a small herbalist store in Nottingham in 1849. The firm quickly expanded to become a chain of chemist shops, with more than 500 stores by 1914.
It remains a fixture on most UK high streets, but it merged with Alliance Unichem in 2006, and finally left British hands in 2007, when Alliance Boots was bought by private equity firm KKR for £11.1 billion.
The Raleigh Bicycle Company was formed in 1890, and by the 1960s it was the biggest cycle maker in the world.
However, the company moved production out of the UK in 2002, and was sold to a Dutch rival in 2012.
The roots of the business were in farming, as early as the 1920s, when a number of businesses were brought together to form Associated Dairies and Farm Stores in 1949.
In the 1960s, when the Asquith Brothers opened the Queen’s supermarkets in Pontefract, Edlington and South Elmsall, the farmers saw the potential, and merged with the supermarkets to form ASDA. In 1999 the chain was sold to Walmart in the US.
The company started life in 1849 as the National Freehold Land and Building Society. It gained its name after merging with the Abbey National Building Society in 1944.
It was the first building society to become a bank in 1989. It then merged with the National and Provincial Building Society in 1996, and the whole lot was sold to Banco Santander in Spain in 2004.
The origins of the company were in the Swallow motorcycle sidecars produced in 1922. The firm moved into car production and adopted the name Jaguar in 1935.
The success of the range of sports cars produced after 1948, and the racing triumphs in subsequent years, made Jaguar a household name. However, in 1989 the company was bought by Ford in the US, and then sold on again to Tata Motors in India in 2008.
The company started in the 1930s with the advent of steam power, as a mail delivery service. It soon expanded services further East, and in 1840 it became the Peninsular and Oriental Steam Navigation Company, carrying mail, cargo, and passengers.
In the 1950s it diversified into tankers, and through the 1990s and 2000s it focused increasingly on its ports around the world. At that point it became an acquisition target - and was sold to DP World in 2006.
The telecoms firm started life in 1985 as Cellnet. At that point it was part-owned by BT, but the telecoms giant later bought the rest of the business. It was spun off from the BT business in 2002, at which point it was named O2.
Just three years later it was sold to Spain’s Telefonica for £18 billion. Part of the agreement was that O2 couldn’t change its name, and it still had to have a headquarters in the UK.
Powergen was formed with the privatisation of the electricity industry between 1988 and 1991. In 1999 it became the first UK company to sell electricity and gas to UK companies via the internet.
After buying a US energy company in 2000, it became an acquisition target itself in 2002. At that point it was sold to German energy group E.on.
In 1974, ten major water authorities were created by the Water Act, the largest of which was Thames Water. In 1989 it was privatised and began a global expansion programme that meant by 1995 it was the third largest water company in the world.
As a result of its global footprint, it was bought by the German utility company RWE in 2001 for £4.8 billion. Four years later it was sold to a consortium led by an investment fund run by the Australian Macquarie Bank for £8 billion.