Prime Minister Theresa May led tributes to the "heroism" of campaigners on the centenary on Tuesday of women winning the right to vote in Britain, as a host of events honouring the Suffragette movement were held.

In a speech in Manchester, the birthplace of Suffragette leader Emmeline Pankhurst,  May will honour thewomen who "transformed British democracy."

Campaigners, meanwhile, hope to make fresh calls for Suffragettes who were jailed while fighting to win the vote for women to be pardoned posthumously.

The Fawcett Society, a British charity campaigning for gender equality and women's rights, is among those urging the country's interior minister Amber Rudd to officially pardon more than 1,000 women jailed during their struggle for equality.

Calls for pardon 

"Voting was a value judgment, not an intrinsic right," she wrote in Tuesday's the Daily Telegraph. "That inequality is one of the reasons why I support calls to offer a posthumous pardon to those Suffragettes charged with righting that wrong." 

Rudd told theBBCshe was aware of the campaign and "completely understand where it's coming from."

Britain's Suffragettes adopted militant tactics in their fight for the vote, including the use of violence. 

They chained themselves to railings, broke shop windows and blew up post boxes as part of their fight. They cut electricity lines, disrupted meetings and even bombed the house of a government minister.

"It is complicated," Rudd said. "If you're going to give a legal pardon for things like arson and violence it's not straightforward."

'Heroic, tireless struggle' 

Organisers of an evening reception to launch a year-long "Vote 100" series of Suffragette events and exhibitions in Westminster have invited every living current and former female lawmaker.

It will be the largest-ever gathering of Britain's  women politicians, organisers believe.

"I look forward to joining hundreds of female Parliamentarians, past and present, to celebrate this very special anniversary," May said ahead of the event.

"Everyone attending tonight will be there because of the heroic, tireless struggle of those who came before us."

In parliament's spectacular central lobby four historic acts of law will go on display together for the first time.

They include the Representation of the People Act, the Parliament (Qualification of Women) Act 1918, which allowed women to become MPs, the Equal Franchise Act 1928, which gave women the vote on the same terms as men, and the Life Peerages Act 1958, which allowed women to sit in the Lords as life peers.

'Real equality' still elusive

A specially-commissioned public exhibition to mark the centenary, featuring life-sized images of central figures of the suffrage movement, was unveiled in London's Trafalgar Square.

This year marks 100 years since parliament passed the law which allowed the first women, and all men, to vote for the first time. 

On February 6, 1918, the Representation of the People Bill became law and added to the voting roll around eight million women who were aged over 30 and met other conditions.

Although it was not until 1928 that British women gained the same voting rights as men, the 1918 act was a major step that put the country far ahead of nations such as France.