Even when confronted with personal sadness the Queen has never flinched from public duty

Iain Duncan Smith, Conservative leader

The prime minister praised "50 years of absolutely dedicated service by Her Majesty and Prince Philip".

He said the public's reaction to the death of the Queen Mother earlier this year showed the "respect and loyalty which monarchy retains in the heart of our nation".

"I know that throughout the Jubilee celebrations we will see the same public support and commitment," Mr Blair told MPs during a short Commons debate.

'Closet Republicans'

Conservative leader Iain Duncan Smith said the Queen "symbolised the superiority of evolution over revolution in our national life".

"Even when confronted with personal sadness the Queen has never flinched from public duty and put her country and her people first," he added.

She was a "lesson in constancy and dedication" to the entire nation.

And "critics and closet Republicans" would be "utterly confounded" by the outpouring of loyalty and affection throughout Britain for the Monarch during Jubilee year, Mr Duncan Smith said.

'Debt of gratitude'

MPs were speaking ahead of the Queen's visit to Parliament next Tuesday, 30 April.

The Queen has lost a sister and a mother

Liberal Democratic leader Charles Kennedy spoke of the "pivotal presence" of the Queen at the heart of the Commonwealth, which remained a "force for good in the world generally."

Mr Kennedy said the country owed a "debt of gratitude" to the Royal Family and he offered his condolences on their recent losses.

He said he was looking forward to welcoming the Queen to his Isle of Skye constituency in a "few weeks time".

Congratulations

Ulster Unionist leader David Trimble said the Queen did not "discharge her functions in a routine or casual way".

The people of Northern Ireland was one of the few institutions common to the whole of the UK.

But unlike some of the other institutions, the people of Northern Ireland never felt neglected by the Royal Family.

Hywel Williams, for Plaid Cymru, and Nigel Dodds, of the Democratic Unionist Party, also conveyed their congratulations to the Queen.

The Queen, who by tradition is not allowed to enter the Commons chamber, will address Peers and MPs in Westminter Hall.

Mr Blair told MPs the Jubilee celebrations, from the 1 to 4 June, would culminate with a National Thanksgiving Service in St Paul's Cathedral.