Baroness Thatcher is said to be "in good spirits" as she recovers from minor surgery but is expected to spend Christmas in hospital.
The 87-year-old former prime minister was operated on three days ago to remove a growth from her bladder after suffering pain earlier in the week.
"I understand she is in good spirits," a spokesman said.
"Given her age, I don't think she will be coming out for a few days."
The veteran ex-premier's public appearances have been very restricted over recent years due to continued ill health.
She was unable to join the Queen for a Diamond Jubilee lunch with former and serving prime ministers this summer and missed an 85th birthday party thrown for her at 10 Downing Street.
In October she was sufficiently well, however, to mark her 87th birthday with lunch at a restaurant in London's exclusive St James's district with her son Mark and his wife.
Her health was thrust into the global spotlight this year when Meryl Streep starred in a controversial Hollywood film, The Iron Lady, about her.
The film drew criticism from Mr Cameron and others for concentrating on the dementia she has suffered after a series of small strokes.