Crying game: what it takes to bring a tear to our MPs' eyes

Welling up: David Cameron, Tony Blair and Ed Balls showing their sensitive sides (Rex Features)

There was a time when it would be career destroying for a politician to admit to shedding a tear.

Margaret Thatcher would never have risked her prized reputation as the Iron Lady with such an admission of weakness – though she was spotted, twice, shedding tears over what she cared about most: once when her son Mark got lost in the Sahara desert, and again when her career came to an end.

Her reticence is understandable, considering the ridicule directed at Bob Maclennan, who took on the leadership of the Social Democratic Party after 1987 when the party was reduced to a rump and was negotiating a painful merger with the Liberals. Maclennan became so frustrated dealing with the immovable David Owen, who refused to be a party to the merger, that one particularly ghastly meeting reduced him to tears. From thereon, he was known derisively as "Blubbering Bob".

But a quarter century later, Ed Balls, Labour's tough Shadow Chancellor, has volunteered a list of occasions when he was lachrymose, unafraid that his enemies might call him "Blubbering Balls", because public attitudes to a tear in the eye of a politician have turned through a full 180 degrees.

Instead of being a cause of shame, it is almost obligatory. The politician who cannot cry is not in touch with his or her feelings, and therefore cannot be expected to be in touch with ours. They cry over such a variety of things, from television shows to beautiful music, that a cynic might wonder if they do it on purpose.

I spoke to a variety of the great and good at the Palace of Westminster yesterday to find out what got those political tear ducts irritated.

Mr Ball's wife, and Shadow Home Secretary, Yvette Cooper has previously told of what makes her weep – so there can't be dry eye in her house. "I even cried watching a Cinderella panto at Christmas," she once told The Guardian.

She is not alone. Louise Mensch the novelist-turned-Conservative MP, told i she can be "reduced to heart-wrenching sobs" by deathbed scenes, particularly those in Downton Abbey. Tessa Jowell was more specific revealing "beautiful music", Anna Karenina and the novel One Day were all enough to cause her tears as well as "when a friend's daughter sang at a 16th birthday party recently".

However, female MPs weren't the only ones to find themselves in tears.

Tom Watson said Anthony Minghella's Truly, Madly, Deeply reduces him to "a blubbing mess every time I see it" and he has watched it 20 times.

Rory Stewart, the swashbuckling Tory, who crossed Afghanistan with a dog for company (it died in 2002) admits "any film, book, play or poem in which a dog dies" makes him weepy.

The Northern Irish politician David Burnside partly identifies with Mr Balls, admitting to crying in front of The Antiques Roadshow.

"But mostly I find great speeches move me," he said. "Oh, and Ed Balls makes me want to cry."