The Tories' plan to leave the European Parliament's main centre-right group is "stupid", an ex-Tory MEP has said.
Leader David Cameron has vowed to take his MEPs out the European People's Party (EPP), saying its federalist views are against Tory policy.
But Caroline Jackson, who stood down on 4 June, said he was swapping Europe's biggest parties for "odds and sods".
But a Conservative spokesman said the party was confident it would "create our new group within a few weeks".
Mr Cameron pledged to cut the Conservatives' ties with the EPP grouping during his 2005 Conservative leadership campaign.
He has insisted the new grouping would "work closely with the EPP on all sorts areas where we agree", adding: "We will be happy neighbours rather than unhappy tenants."
Ms Jackson, who was first elected as an MEP in 1984, told BBC Radio 4's The World Tonight she believed a majority of her outgoing Conservative colleagues in the European Parliament shared her views but did not speak up because they did not want to "rock the boat".
It was wrong to put such emphasis on a "symbolic point about federalism", she said, when the Parliament itself was not responsible for European integration.
Mr Cameron pledged to leave the EPP in his 2005 leadership campaign
She added "people are not queuing up to join the Conservative MEPs" and said the party was putting at risk the influence it enjoyed in the EPP by sitting alongside Europe's largest political delegations.
"Exchanging that for a few random Latvian nationalists and the odd Hungarian you find that under the political hedge - that is, I think, a very misguided policy," she said.
To qualify as a grouping and get access to EU funding, the Conservatives would have to be joined by MEPs from at least six other countries.
It is thought likely they will form an alliance from the Czech Republic's Civic Democrats and Poland's Law and Justice Party.
Tory MEP Neil Parish has now begun sounding out likely partners from other centre-right factions.
The Conservatives won 26 MEPs on 4 June's elections, including Northern Ireland's Jim Nicholson of United Conservatives and Unionists - New Force.
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