Scotland Office minister David Mundell says the Conservatives will "give no quarter" to the Lib Dems at the next general election.
Scottish Political Editor Peter MacMahon writes about the Conservatives' devolution journey north of the border.
The leader of the Scottish Conservatives has called on the national party to help fight for the union to remain intact.
Today represents a great loss for our country. Margaret Thatcher was greatest PM of post-war era. A privilege and honour to have known her.
Labour will suspend campaigning in the local elections until further notice following the death of Baroness Thatcher, senior party sources have told the Press Association.
Former PM Tony Blair has paid tribute to Lady Thatcher:
“Margaret Thatcher was a towering political figure.
Very few leaders get to change not only the political landscape of their country but of the world. Margaret was such a leader. Her global impact was vast.
And some of the changes she made in Britain were, in certain respects at least, retained by the 1997 Labour Government, and came to be implemented by governments around the world.
As a person she was kind and generous spirited and was always immensely supportive to me as Prime Minister although we came from opposite sides of politics.
Even if you disagreed with her as I did on certain issues and occasionally strongly, you could not disrespect her character or her contribution to Britain’s national life.
She will be sadly missed.
Jon Swaine, of the Daily Telegraph, has spoken to Diane Thatcher about the death of her former mother-in-law.
Diane Thatcher, mother of Lady Thatcher's grandchildren, tells me from Texas: "My children & I are heartbroken .. she will be dearly missed"
Former Conservative prime minister Sir John Major described Baroness Thatcher as a "true force of nature" and a "political phenomenon".
In government, the UK was turned around under - and in large measure because of - her leadership.
Her reforms of the economy, trades union law, and her recovery of the Falkland Islands elevated her above normal politics, and may not have been achieved under any other leader.
Her outstanding characteristics will always be remembered by those who worked closely with her: courage and determination in politics, and humanity and generosity of spirit in private.
In 1982 Argentina invaded the Falklands. Following reports British troops had recaptured the island of South Georgia from Argentina, she told reporters asking questions of her: "Just rejoice at that news."
Kelvin MacKenzie, editor of The Sun from 1981 to 1994, told ITV News that Margaret Thatcher "had an umbilical cord in difficult times to the voter".
He added: "We don't have leaders like that at the moment. It might be a different time. She was a sensation and her Thatcherite legacy will be something that will haunt the Conservative Party for decades to come."
Downing Street has confirmed that Baroness Margaret Thatcher will be given a Ceremonial funeral:
Downing Street can announce that, with The Queen's consent, Lady Thatcher will receive a Ceremonial funeral with military honours. The service will be held at St Paul's Cathedral. A wide and diverse range of people and groups with connections to Lady Thatcher will be invited.
– Downing Street statement
The service will be followed by a private cremation. All the arrangements being put in place are in line with wishes of Lady Thatcher's family. Further details will be published over the coming days.
Anne Widdecombe, former Conservative minister, told ITV News: "She was a very, very determined lady and a great legacy for women because there is an entire generation that, from the time they were five-years-old until the time that they had their first vote, knew nothing except a woman in charge."