David Cameron is to make his long-awaited speech on Britain's future relations with the European Union in the Netherlands on Friday.
The Prime Minister had previously been expected to wait until next week to make the address, in which he is likely to set out plans for a referendum on a new settlement with Brussels after the next general election in 2015.
The announcement of the date of the speech was made on the No 10 Twitter feed. It had previously been thought that Mr Cameron was planning to make his speech on January 22, though this date was never officially confirmed.
Mr Cameron will meet Dutch prime minister Mark Rutte for talks during his visit to Holland, but Mr Rutte is not expected to attend the speech. The Prime Minister's audience will be made up of business people, EU diplomats and other interested parties, Downing Street said.
Reports suggested that the plan had to be changed to avoid clashing with German and French celebrations of the 50th anniversary of the 1963 Elysee Treaty which formally established reconciliation between the two countries following the Second World War.
Asked why Mr Cameron had chosen to make a speech on his approach to Britain's future relations with Europe in the Netherlands, his official spokesman said: "I think giving the speech in a founding member of the European Union, a country that has - not dissimilar to the UK - a strong global-trading, outward-looking history, is entirely appropriate.
"He sees it as important to set out his view about it being in the British national interest to remain in the EU but with a changed relationship."
Earlier, Mr Cameron made clear that any referendum should take place only after Britain's relationship with the EU had "fundamentally" changed. The Prime Minister dismissed the idea of an immediate in/out referendum, insisting that would be putting a "false choice" in front of voters.
But he said he was "not against a referendum" altogether and was in favour of one "in some cases".
Amid claims from some in his party that it might be in Britain's interests to leave the EU, the Prime Minister said: "I'm in favour of our membership of the European Union and I'm optimistic and confident that we can achieve changes in the European Union to make sure that Britain feels more comfortable with our relationship with Europe."