David Cameron said he and other democratically-elected leaders should pick who gets top EU jobs as he arrived for talks with key counterparts amid continued efforts to block Jean-Claude Juncker from becoming president of the European Commission.
The Prime Minister is at the country residence of Fredrik Reinfeldt, where he was pictured being taken for a traditional row on a lake by the Swedish premier along with German chancellor Angela Merkel and Dutch PM Mark Rutte.
As he arrived for the pre-scheduled talks over the future direction of the EU, Mr Cameron said: "As the democratically-elected leaders of Europe, we should be the ones to choose who should run these institutions rather than accept some new process which was never agreed.
"I think that is important."
The visit came as Mr Cameron's position was bolstered by support from Labour, which announced it would not back the former Luxembourg Prime Minister in his bid to be named when Jose Manuel Barroso steps down after eight years in the autumn.
Mr Juncker is the candidate of the centre-right European People's Party - the largest grouping in the European Parliament following last month's elections, but is regarded in London as an arch-federalist and opponent of reform, whose appointment would make UK departure from the 28-nation bloc more likely.
Under the Lisbon treaty, the European council - made up of the leaders of the 28 members states - is supposed to to "take into account the elections to the European parliament" in choosing a candidate for the presidency - who must then be approved in a vote of MEPs.
But Mr Cameron is seeking to secure enough allies to create at least a blocking minority in the Council against Mr Juncker under the qualified majority system, which gives added weight to the votes of bigger countries.
Foreign Secretary William Hague has insisted there are other "talented candidates" for the presidency of the European Commission and stressed the need for the senior roles in Brussels to be filled by people who recognised it could not be "business as usual" in the EU.
Labour has said its MEPs will not vote for Mr Juncker in the European Parliament, where the EPP is far short of an overall majority.
A party spokesman said: "The nominee for European Commission president is ultimately a decision for the European Council, including David Cameron.
"Labour will not support Jean-Claude Juncker as a candidate for president of the European Commission. Should Mr Juncker be put before the European Parliament, Labour MEPs would vote against him.
"The message from the European elections was clear - that we need reform in Europe. We need reform so we can promote jobs and growth.
"Mr Juncker's record shows he would make these reforms more difficult."
In Sweden Mr Cameron will hold talks with Mr Reinfeldt, Mr Rutte and Mrs Merkel on reforms in Europe.
Mr Cameron's official spokesman said the issue of candidates for the EU's top jobs was not on the formal agenda for talks in Sweden, but they were likely to be discussed in the margins of the meeting.
The four leaders have not met in this format before, said the spokesman, who stressed that the meeting had been "months and months" in the planning and was not an emergency response to the recent row over Mr Juncker's candidacy.
Over a working dinner this evening, the four leaders will discuss economic and institutional issues, while tomorrow morning's working session will concentrate on wider policy issues, including the crisis in Ukraine, said Downing Street.
The regular weekly Tuesday meeting of Cabinet will be held back until the afternoon to allow the Prime Minister time to return to the UK.