Tony Blair today takes his place in the top ten long-serving British prime ministers of all time.

The MP for Sedgefield, County Durham, will start the New Year in tenth spot by knocking Herbert Asquith from the list.

By passing Asquith's eight years and 244 days in the top job, between 1908 and 1916, Mr Blair also becomes the second-longest serving Prime Minister of the past 100 years.

On Tuesday, Mr Blair seized Winston Churchill's record of eight years and 240 days, amassed during two terms in Downing Street.

Speculation is already mounting over whether Mr Blair will attempt to knock former Tory PM Margaret Thatcher further down the chart. To overtake the Iron Lady's 11 years and 209 days, Mr Blair would have to stay on until November 2008.

Mr Blair has indicated he plans to serve a full third term before stepping aside at the next General Election, though few expect him to remain Labour leader for that long.

Mr Blair's constituency agent, John Burton, said: "In Sedgefield, we are very proud of him and we would like to see him stay in post for a long time. But I'm sure that breaking records and overtaking previous prime ministers' length of service never crosses his mind."

Elections expert David Butler said: "I think people do take pride in length in office and it does affect behaviour.

"Mr Blair may want to beat Baroness Thatcher's 11 and a half years, but I think it is rather vulgar to get involved in these calculations."

In his New Year message, Mr Blair makes clear his determination to press ahead with his controversial reform agenda for schools, local health services and welfare, as well as to take crucial decisions on the future of pensions and nuclear power.

And he pledged that the Government would not "let our resolve slip" in the battle to defeat terrorism at home and abroad, and bring peace and democracy to Iraq and Afghanistan.