From Margaret Thatcher to Nigel Farage, euroscepticism has been a proud and virulent strain in British politics for decades -- and could eventually force the country out of the EU altogether.
If Prime Minister David Cameron`s Conservative Party wins a May 7 general election, a referendum on Britain`s membership of the European Union will be held by 2017.
And if Britain then votes to leave, it would be a triumph for anti-EU lawmakers in Cameron`s party and many ordinary people across the island nation who, encouraged by an often hostile mainstream media, are profoundly suspicious of the European Union.
Opinion polls indicate that more people in Britain support EU membership than oppose it but a vociferous minority is against and even pro-European parties like opposition Labour keep their support discreet.
"The most difficult thing about the referendum is that the arguments in favour are complicated, economic, numerical and rational," said Charles Grant, director of the Centre for European Reform think tank.
"The arguments against are simple, emotional and romantic: do you want to be ruled by foreigners or not?" he said.
Despite the difficulties, the warnings against "Brexit" have multiplied in recent weeks -- including from some of Britain`s biggest businesses.
Open Europe, another think tank, said in a report that under a worst case scenario leaving Europe could cause the economy to shrivel by up to 2.2 percent -- equivalent to £56 billion (77 billion euros, $83 billion) a year -- by 2030.The word euroscepticism seems first to have been used by The Times newspaper in 1986 but its roots go back further than that to an imperialist mindset.
"It has an outsider tradition, a narrative about who the British are and that tradition is very sceptical of the country restricting its horizon to the EU," said Oliver Daddow, a senior lecturer in international relations at the University of Chichester.
With a democratic tradition extending centuries and having avoided occupation during World War II, unlike other European nations, Britons often have a pride in their political structures which can risk coming across as arrogance.
Figures as diverse as 1980s prime minister Thatcher and Farage, whose UK Independence Party wants Britain to leave the EU, have gained significant political capital from euroscepticism.
Many in Britain believe the EU`s role should be purely economic and that it should stay out of domestic politics.
Cameron has repeatedly said that the EU is "trying to take too much power" and wants to renegotiate Britain`s relationship with it before the referendum although he has not yet spelled out exactly how.
Britain did not become part of the European single market until 1975, overcoming French vetoes, and has since negotiated significant opt-outs.
It does not use the euro, is not a member of the Schengen free movement area and receives a significant rebate from yearly budget contributions.
"From Britain`s perspective, it has never been totally committed to European integration as an end in itself because it always felt it has other options in the world" such as ties with the United States, said Tim Oliver of the London School of Economics.But even the economic relationship with the rest of the European Union was thrown into question by the aftermath of the 2008 financial crisis.
"The eurozone crisis means that Europe is associated with high unemployment, nasty populist parties, economic failures and bad leadership," Grant said.
"That`s the single biggest reason why euroscepticism has done very well recently."
Grant added that UKIP, which came top in last year`s European elections in Britain, had also succeeded in associating immigration with the EU in voters` minds.
Cameron promised a referendum in 2013 in the face of intense pressure from his party.
But most Britons do not see Europe as a major issue in the election -- it came only ninth behind the state-run National Health Service (NHS), the economy and immigration in a BBC poll in January.
While euroscepticism is widespread among voters, polling suggests this may not be enough for them to want to leave, if they do get the chance to vote.
The latest YouGov poll in February found that support for membership was at an all-time high -- 45 percent -- compared to 35 percent in favour of leaving.
