Who, what, why: What is the parliamentary dress code?

MP Harriet Harman has worn a T-shirt with a feminist slogan to Prime Minister's questions. But what is the parliamentary dress code, asks Lucy Townsend.

Men should wear a shirt and tie. Women are expected to dress in smart businesslike attire. Slogan T-shirts are not allowed.

But Harriet Harman's T-shirt, with the words "this is what a feminist looks like", is the latest in a string of sartorial statements made by MPs.

In 2013 Green Party MP Caroline Lucas was asked to cover up her T-shirt emblazoned with the words "No more page three", which she wore to a debate on media sexism. Chairman of the session, Labour's Jimmy Hood, told her to "put her jacket back on" and comply with the dress code.

Labour's Kevin Brennan called for dress-down Thursdays in the House of Commons in 2002, but was rebuffed as he stood up to speak without wearing a tie. Speaker Michael Martin said in response, "What my feeling would be is - jackets and tie for honourable gentlemen."

Breaking with convention has always been a way of making a political point. Oliver Cromwell wore plain, and not very clean, linen made by a country tailor, and a hat without a hat band, according to a House of Commons factsheet. His fellow Puritans dressed similarly.

But for others it is just about style.

In 1900, a new set of rules had to be written to clarify the etiquette regarding tall hats, which had become fashionable.

The author Alfred Kinnear MP, wrote: "At all times remove your hat on entering the House, and put it on upon taking your seat and remove it again on rising for whatever purpose. If the MP asks a question he will stand, and with his hat off and he may receive the answer of the Minister seated and with his hat on."

Until 1998, MPs were able to wear an "opera hat" to draw attention to themselves to raise a point of order. Two of the black top hats were kept in the Commons, but they were scrapped by the Select Committee on Commons Modernisation because they made the House "look ridiculous".

"There are still tags in the cloakroom for MPs to hang their swords on," says journalist Quentin Letts. "It's a little red ribbon next to their coat hooks.

"I did see a male MP come in once with no tie and an anorak. Nothing was said but he didn't catch the speaker's eye. That tends to be how it works."

The deputy Labour leader's T-shirt is part of a campaign by The Fawcett Society and Elle magazine. It is not known whether the Speaker had noticed it.

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