Leaving the European Union and following the "Norway model" risks Britain either being reduced to a “fax democracy” but could empowered the country to be ''rich" and able to catch fish.
Europhile former Lib Dem leader Nick Clegg and avowedly anti-EU Ukip leader Nigel Farage today offered polarised views of British life if the country became like the Nordic state, which enjoys access to the single market without joining the EU.
It came after David Cameron dismissed the the idea of a semi-detached relationship with Brussels, saying he would "guard very strongly against" emulating Norway - his clearest signal yet of his pro-EU inclinations - while in Iceland for a summit of Northern European leaders.
The Prime Minister is attempting to trash out a deal with EU leaders to claw back powers from Brussels, before putting it to the public in an in-out referendum on Britain's membership of the EU.
While some say the "Norway option" is a red herring that few actually support, Mr Clegg argued the country has access to the European trading zone "but have to wait by the fax machine for Brussels to send them the rules”.
"We would be left powerless and voiceless, waiting, like the Norwegians, by the fax machine,” he wrote in The Independent.
Mr Farage, who clashed with the Lib Dem MP over Europe in televised debates last year, takes the polar opposite view. "The Prime Minister is saying how ghastly Norway is," he told the LBC radio station. "They're rich, they top the world's happiest index, they're allowed to catch their own fish."
Which way out? Mooted options for a "Brexit" include:
"The Norway model"
Norway is a member of the European Economic Area – an association of all 27 EU member states, plus the three non-EU members. It grants the country the "Four Freedoms" - free movement of goods, services, persons and capital. In return, it has to implement all the EU’s laws relating to that internal market. Less regulation, say proponents, but no say over areas areas it would be forced to adhere to.
"The Switzerland model"
The Free Trade Agreement of 1972 established the "EU-Swiss" relationship, which has since been fleshed out by two treaties that mean Switzerland has a large degree of access to the single market. Switzerland does retain more sovereignty than Norway or EU member states, but its deal does not include free use of services.
"The Turkey option"
Turkey is a member of the "customs union", giving it free trade in goods with the EU and upholds the European tariff on
on imports from other countries. As with the Swiss and Norwegian options, Turkey is exempt from binding farming and fishing policies, and pays less in into the EU budget than the other two. But it has no influence over the rules of the customs union or the other rules it has to implement to comply.
"The Free Trade Agreement Option"
The EU has a treaty-bound legal commitment to free trade with its neighbours, so Britain would be a priority for an agreement given the historic ties. The EU already has "FTAs" with developed economies including Canada, South Korea, South Africa - but critics say even if a deal was done it would mean a reduced trading arrangement.
Robert Oxley, a spokesman for Vote Leave, told HuffPost UK that "In" campaigners were peddling "scare stories" about countries outside the EU.
He said: "The Norway option is the deal that Norway negotiated and is an arrangement with which the vast majority of Norwegians are happy with - as polls consistently show. The Icelandic option is a model that works for Iceland and whose Prime Minister has said has been 'instrumental' in the country's economic success.
"Despite the claims to the contrary from the Britain Stronger In Europe campaign and David Cameron that do Britain down, we will negotiate our own deal.
"If we make the safer choice and Vote Leave, Britain will negotiate it's own British option that will be based on free trade and friendly economic cooperation. Scare stories about other countries deals that they themselves are perfectly happy with should be treated with the contempt they deserve."
Will Straw, executive director of Britain Stronger In Europe, said "Brexit" supporters had to "own up" over their alternatives.
He said: “Generalised assertions that Britain could prosper while standing alone from our largest trading partner are unacceptable in a debate of this magnitude. Not to mention the fact that the rest of the EU would have to agree to any deal.
“If the leave campaigns cannot outline their proposed alternative economic and trading arrangement for Britain outside the EU, people will conclude they are either concealing the truth or that they do not know. Either way, Britain would be weaker."