Odinga's withdrawal had fueled speculation about whether the vote would go ahead at all.
President Uhuru Kenyatta of Kenya confirmed Friday that he had received the controversial election amendment bill from Parliament, saying he will consider before signing it into law.
Stewart issued the statement following a meeting with Foreign Affairs Principal Secretary Monica Juma and opposition leader Raila Odinga at the Foreign and Commonwealth Office in London.
Odinga has argued that his withdrawal from the race forces the IEBC to cancel the election and begin the whole process from scratch - allowing more time for his reforms. To maintain pressure, his opposition National Super Alliance (NASA) coalition called supporters to the street, saying protests would take place every day from next week. Doctor Juliana Otieno at the Jaramogi Oginga Odinga Hospital - named for Odinga's father - said three patients had been admitted with gunshot wounds. One is badly injured. In Nairobi police briefly teargassed protesters who threw stones at passing cars.
The election laws changes were ordered by the Supreme Court, which identified a lacuna it said needed to be filled, when it annulled the August 8 elections citing irregularities.
Opposition leaders have called for daily demonstrations. The decision was hailed across the globe and held up as an opportunity to deepen Kenyan democracy, however the process quickly turned sour, with increasingly ugly rhetoric including attacks by Kenyatta on the judiciary.
"What we are demanding is that the electoral commission should respect the Supreme Court and carry out elections in accordance with the ruling, ".
The protests come as Kenya is mired in confusion over a presidential election that is due to take place in less than two weeks, on October 26. Odinga is betting on a ruling by the Supreme Court after 2013 elections - in which he failed to have the result overturned - which sought to clarify what happens if an election is invalidated.
Opposition legislator James Orengo said the law will lower safeguards against vote-rigging by making the preferred system of transmitting election results a manual one. "The ball is now in the president's court", said Duale.
Meanwhile, analyst Murithi Mutiga said that the withdrawal means that Kenya is in "uncharted waters".
Three people have been shot dead in Bondo town and several others injured as police clashed with protesters in Nasa's anti-IEBC protests. Kenya adopted an electronic system following the flawed 2007 election which sparked ethnic violence that left more than 1,000 people dead.
Kenyatta's Jubilee Party has pursued changes to the electoral law that the opposition says will make it more hard for the Supreme Court to nullify a presidential election and will reduce safeguards against electoral fraud.