The Times that the loss to Britain of being in the EU's single market would be "marginal" and that "not Europe but globalization" was key to economic growth.
His comments fanned the debate in Britain over an EU exit and are likely to have irked Conservative Prime Minister David Cameron, who in January announced plans to renegotiate Britain's relationship with the EU and hold a referendum on the results by 2017.
The premier has been under pressure from the eurosceptic wing of his party for the past year, set to increase after the eurosceptic UKIP party made huge gains in local polls last week, mainly at the expense of the Conservatives.
But Cameron remained "confident" that his strategy would "deliver results," a spokesman said.
"The prime minister has always been clear - we need a Europe that is more open, more competitive, and more flexible; a Europe that wakes up to the modern world of competition. In short, Europe has to reform," the spokesman said.
"But our continued membership must have the consent of the British people, which is why the prime minister has set out a clear timetable on this issue," he added.
UKIP leader Nigel Farage tweeted, "Lord Lawson's article in The Times today legitimizes the Ukip position and exposes serious divisions in the Tory Party."
Lawson dismissed any changes Cameron may be able to negotiate in a new settlement as "inconsequential," saying the EU would be unlikely to make any concessions.
“Moreover, to make exceptions for one member state would inevitably lead to similar demands from others and threaten a general unraveling," he wrote.
A former British Chancellor has called on the UK government to leave the European Union for the good of the country, media reports say.
The call by Nigel Lawson, the chancellor of former premier Margaret Thatcher, was made on Tuesday, days after a eurosceptic party gave his Conservative party a drubbing in local elections.
The Chancellor of the Exchequer between 1983-89 wrote in