Denis Thatcher back in hospital

Sir Denis left hospital smiling in January

Sir Denis Thatcher has returned to hospital for tests in the wake of his heart by-pass operation earlier this year.

A spokesman for the Thatcher family said Sir Denis, husband of former prime minister Margaret, had been feeling unwell last week.

The 88-year-old was re-admitted to the Royal Brompton Hospital on Thursday.

He is said to be in good spirits and has received several visits from Baroness Thatcher.

His son Mark has flown to London from his home in South Africa to be at his father's bedside.

His daughter Carol, who spends much of her time in Switzerland, is also in London.

'Gin drinking'

The family are still awaiting the results of a series of tests but the spokesman said Sir Denis's condition was "not as dramatic as some of the press have made it seem".

Because of the major surgery Sir Denis underwent in January, doctors felt it was best for him to return to hospital "as a precautionary measure to do tests on him and find out what was wrong".

The spokesman said it was not yet known whether Sir Denis' current ill-health was connected with his heart.

Sir Denis left hospital 11 days after his heart by-pass, with doctors calling the operation a "complete success".

His daughter, Carol, put his quick recovery down to "copious gin drinking".

Last year, Baroness Thatcher turned down an invitation to visit the Falklands, saying the trip would have been "too gruelling" for her husband.

The trip would have marked the 20th anniversary of the battle to recapture the islands.

Long marriage

Sir Denis is said to have been the key influence in persuading his wife to bow out of public speaking after she suffered a series of slight strokes.

She has defied doctors, however, by attending a number of functions.

Baroness Thatcher said she could not have made it to the top without him.

They have been married for more than 50 years, including 11 at Downing Street.