The U.K.'s future in Europe returned to the political agenda on Tuesday after a former finance minister said the case for a British exit from the European Union "is clear."
Nigel Lawson, who served as chancellor of the exchequer under Margaret Thatcher in the 1980s, said the EU had passed its "sell-by date" and had become "a bureaucratic monstrosity" from which the U.K. should break free.
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In an opinion piece in The Times newspaper, Lawson said the economic gains from an exit "would substantially outweigh the costs" and that any attempts by the prime minister to renegotiate the U.K.'s membership of the EU would be "inconsequential".
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"The heart of the matter is that the very nature of the European Union, and of this country's relationship with it, has fundamentally changed after the coming into being of the European monetary union and the creation of the euro zone, of which - quite rightly - we are not a part," he said.
Though a number of members of Prime Minister David Cameron's Conservative party are known euro skeptics, Lawson is the most prominent former politician to comment on the country's future relationship with the EU.
Last week, U.K. Prime Minister David Cameron indicated that a referendum on EU membership could beheld earlier than he initially planned.
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In an interview with the BBC on Wednesday, Cameron indicated he could introduce a bill in the new parliamentary year to pave the way for a referendum on Britain's future in the economic bloc. Cameron had said in February that he would re-negotiate Britain's EU membership and planned to hold a referendum on the subject by 2017 if his Conservative party won another term in power in the 2015 elections.
Nigel Lawson said it was"by no means assured" that Cameron would win the 2015 general election and said he believed public demand was such that a referendum would have to happen under any party.
That point has been borne out by recent local elections in the U.K. where the U.K. Independence Party (UKIP), once dismissed as an anti-Europe fringe party which advocates leaving the EU, made major gains.
Lawson added that Brussels would fear a "general unraveling" as other countries sought to match the return of powers.
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There has been a growing chorus of disenchantment with the 27-member European Union and the smaller bloc of countries that use the euro. Earlier this week, the German finance minister who helped launch the euro called for the single currency region to be broken up.
The Queen's Speech
The first indication of the U.K.government's plans could come on Wednesday when the Queen officially marks the start of a new parliamentary year when she sets out the legislative agenda for the year ahead.
On Tuesday, an organization of business leaders said the Queen's statement "may be last chance to unleash business" in the U.K.
(Read More: UK Economy Grows, but Struggle Lies Ahead)
The U.K.-based "Institute of Directors" called for the introduction of three bills to boost business and the economy, including one that would "strip back" European employment directives.
"Successive Governments have implemented EU directives over-zealously, resulting in greater burdens for business than necessary…The government should introduce a bill to strip back all of this 'gold-plating', and make it clear that in future only the minimum required by the directive will be brought into U.K. law," the IoD said in a statement on Monday.
"This is probably the government's last chance in this parliament to announce new legislation to boost businesses and the economy. Nearly half of businesses think that regulation is holding them back. Ministers must seize this opportunity to tackle the issue head-on,"Simon Walker, Director General of the IoD.
-By CNBC's Holly Ellyatt, follow her on Twitter @HollyEllyatt