Norway's foreign minister has urged the UK to assess the advantages of staying in the European Union, rather than consider leaving.
Norway is not in the EU but has access to the single market. UK Eurosceptics use it as a model for how the UK could relate to the EU from outside.
But Foreign Minister Espen Eide said Oslo had "limited scope for influence".
"We are not at the table when decisions are made," he told Radio 4's The World This Weekend.
Mr Eide is pro-EU, though Norwegian voters have twice rejected the chance to join the EU in referendums in 1972 and 1994.
Sir Nigel Sheinwald, a former UK ambassador to the US and to the European Union, said: "The issue is - do you want to be part of the single market? All the economic indicators are that the UK needs to be.
"But [the Norwegians] have no role in negotiations... they have no impact, no influence and there's no accountability. So this is regulation without representation.
"It's the first thing the UK needs to decide, whether it wants to be associated with the single market, from the inside or the outside.
"If on the outside, both the Swiss and the Norwegian models give you no actual impact on the substance of what's agreed."
Conservative MEP Daniel Hannan said he was "not aware of any British Eurosceptics who are arguing that we should precisely replicate the Norwegian model".
He added: "What we're after is something a bit more like what the Swiss have, but actually I think we could get better terms than either Norway or Switzerland."
Prime Minister David Cameron has consistently said he supports Britain's continued membership.
He has hinted, however, at a possible referendum to allow the British people the opportunity to give their "fresh consent" on the issue.
Mr Cameron is expected to give a much delayed speech on Europe early in the new year.
The World This Weekend was broadcast on Radio 4 at 13:00 GMT on Sunday.