Hammond is latest big name to walk away as election campaign starts

As campaigning for December's United Kingdom general election finally got under way, Philip Hammond, who was chancellor under former prime minister Theresa May, announced he is to stand down as a member of Parliament after a series of clashes with Prime Minister Boris Johnson over the issue of Brexit.

Hammond, who had represented the seat of Runnymede and Weybridge for 22 years, and won almost 61 percent of the vote at the last election in 2017, had the Conservative whip withdrawn in October after opposing leaving the European Union without a deal.

He said he was "saddened" at being forced to stand down because he would have his membership taken away if he stood against an official Conservative candidate.

"I will remain as a party member and I will continue to make the case for doing whatever is necessary to deliver a negotiated close future trade and security partnership between the UK and the EU," he wrote in a letter to constituents.

Hammond's announcement came just a week after he said "It really doesn't matter how many times my party kicks me, abuses me, reviles me, they are not going to stop me feeling like a Conservative … and I am not ready yet to give up fighting for the soul of the Conservative Party," and sees him move from being at the heart of government in July to out of Westminster altogether in November.

The news came as Johnson went to Buckingham Palace to inform the Queen officially of the election, the country's first December election in almost 100 years, and its third general election in four years, and was just the latest in a string of announcements from Conservative and former Conservative MPs who have announced they will not be seeking re-election.

Several Labour MPs will also not be standing again but it is the high-profile nature of the Conservatives that is particularly notable.

While some, like another former chancellor, Kenneth Clarke, who was also the longest-serving member in the House, are quitting because they have done their time, others, particularly female MPs, are quitting while still seeming to have plenty of time left in their careers, hinting at a change in the tone of the political environment and debate - which in turn suggests what the future atmosphere in Westminster could be like.

Former education secretary Justine Greening, another Brexit rebel, has walked away aged 50, saying she can "achieve more positive change outside Parliament", and having also told the BBC "it would be very hard for me to vote for the Conservatives, if I'm looking at what they stand for on Brexit."

Amber Rudd, who used to be home secretary, is quitting at the age of 56, and Culture Secretary Nicky Morgan, 47, is also leaving, citing the "clear impact" on her family and "the other sacrifices involved in and the abuse for doing the job of a modern MP".