News of the highly symbolic meeting coincided with a row over Irish government calls for powerful cross-border bodies to oversee the north.
Mr Blair's spokesman said Sinn Fein would be invited to Downing Street on the afternoon of 11 December, and Mr Adams would be treated "like any other leader involved in the peace process". There will be no public handshake, but the Sinn Fein president will be allowed to address the media outside No 10.
Mr Blair and Mr Adams met in October at Stormont, but the republicans, who yesterday welcomed the move, have been pressing for a Downing Street meeting. A delegation of about four, including Martin McGuinness, is likely to attend the 45-minute meeting.
Mr Blair's office said the Prime Minister would use the meeting to discuss the peace talks and reiterate the need for a commitment to exclusively peaceful means. Sinn Fein chairman Mitchel McLoughlin said his delegation would raise "the British claim to jurisdiction over this part of Ireland which we believe lies at the heart of the conflict".
The announcement provoked fury from the Ulster Unionists with Ken Maginnis, MP, the party's security spokesman, saying it was an "insult for families of IRA victims". The Conservative Party said that the decision to meet Mr Adams and Sinn Fein at No 10 was "premature".
Earlier, the Irish foreign minister, David Andrews, provoked Unionist fury by saying his government wanted to see cross-border bodies set up with powers "not unlike a government". On BBC Radio Ulster's Inside Politics he said: "A cross-border body with executive powers would mean representatives from the devolved government in the north participating with ministers from the parliament in the south and they would reach joint decisions." Decisions "would be implemented by a secretariat who would have strong functions, executive functions and directional functions not unlike a government".
Reg Empey, a member of the Ulster Unionist talks team, said the idea was "utterly unacceptable to Unionists".
The Northern Ireland office hinted at its irritation at Mr Andrews' call in a carefully-worded statement which said it covered "crucial issues in the talks" and that "words used are important".Reuse content