Mr Portillo, a leading Euro-sceptic in the Cabinet, called for "tolerance" in the party after Sir George's Reigate constituency voted to deselect him on account of his disloyalty to the Prime Minister over the Government's refusal to rule out a single European currency.
"George was extremely unwise and very rude to make some of the remarks he made about the Prime Minister," said Mr Portillo. "However, I believe we are a tolerant party and I am sorry to see people being asked to leave their seats after they have given good service to their constituents.
"I hope we can continue to show tolerance towards a very broad strand of opinion. We are a very broad church."
During a visit to a British Aerospace factory in Lancashire, which is engaged in the Eurofighter project, Mr Portillo admitted that Sir George's actions had not been helpful to the Conservative cause in the run-up to a general election.
"Everyone should be careful about what they say and bear in mind the consequences of what they say. But even if they say things out of line, I hope we can show tolerance for them."
He advised the rebel MP not to stand as an independent. "I only support candidates who are Conservative, so George must bear that firmly in mind," he said.
John Major sidestepped a question about how sad he was over the departure of Sir George, who was deselected after describing the Prime Minister as Kenneth Clarke's "ventriloquist's dummy".
Mr Major said he believed the independence of the Tory constituency associations was a very great strength within the Conservative Party, which he had no intention of changing.
"That means that the selection of candidates is a matter entirely and completely for the constituency parties and I have not in the past, will not now, will not in the future, interfere in their selections of candidates," said Mr Major.
Sir George was saying nothing yesterday about his deselection.
The blinds were drawn at his home, near Dorking, and the telephone was off the hook. His wife answered the door, but only to tell reporters: "I can't comment at all. My husband will not make a statement for another few days."
Lady Gardiner later left their home, saying that her husband was not there, and she would not speculate on reports that he was consulting solicitors about the legality of the vote.
His constituency association has already begun the process of trying to find a new candidate to replace Sir George at the next election.Reuse content