Plans to allow women in Saudi Arabia to vote and stand for election in local polls has been hailed as a "significant step forward" by Foreign Secretary William Hague.
He said the UK would examine the detail of the reforms announced by King Abdullah "and how they will work in practice".
The changes, agreed with senior clerics, will come into force for elections in 2015 and arrive amid internal pressure in the deeply socially conservative country.
Women's groups in the Muslim kingdom have also taken inspiration from the Arab Spring uprisings to openly defy a ban on females driving.
"We refuse to marginalise the role of women in Saudi society and in every aspect, within the rules of Sharia," the king said.
"Balanced modernisation, which falls within our Islamic values, is an important demand in an era where there is no place for defeatist or hesitant people."
Women will also be eligible in future for appointment to the Shura Council, which offers policy opinion and debates plans for the economy and society, he said.
The introduction of the vote will not be implemented in time for women to take part in the next round of municipal elections on Thursday.
Mr Hague said: "I welcome the reports of a proposal for women in Saudi Arabia to be given the right to vote and run in future municipal elections.
"This would be a significant step forward for the people of Saudi Arabia. The UK strongly supports moves to increase the political and economic participation of women across the Arab world."
The Press Association, photo by Foreign and Commonwealth Office