The Staggers 18 February 2016 "Continuity Cameron" may well be the best shot for those vying to replace him Tim Montgomerie's resignation isn't news in of itself - but what it indicates is interesting. Photo: Getty Sign UpGet the New Statesman\'s Morning Call email. Sign-up At first glance, Tim Montgomerie's resignation from the Conservative Party is a story that is only of interest to the Westminster bubble - and even, then, only for an hour or so. But that the Times columnist and the founder of ConservativeHome has walked out of the party has big implications for the country. As I've written before, Britain is on the cusp of a political first: for the first time in British history, the prime minister will be chosen not at a general election or by members of Parliament, but by party activists. If Labour's current trajectory is replicated at a general election in 2020, that Prime Minister will be in office with a large majority, quite probably for a decade or a more. It is entirely plausible that Conservative party members will pick the next two prime ministers. Who they are matters a great deal. Just as pets tend to resemble their owners, parties begin to resemble their leaders after a while. After thirteen years of Tony Blair and Gordon Brown, party members voted overwhelmingly for the "continuity candidate", David Miliband. Although Montgomerie's resignation is more complicated than "Cameron's not right-wing enough" or "Cameron's not left-wing enough", what really matters is that he's left because David Cameron's is too much like David Cameron. My impression from talking to both former and current Conservative members is that his journey is very much not a lonely one. The Tory party is smaller now than it was when Cameron became leader. But it's also far more Cameron-inclined - and likely to become more so. That means that the candidate who can most effectively present themselves as "continuity Cameron" may well be in a sweeter spot than backing Leave, promising a return to untramelled Thatcherism, or even being able to win the Labour stronghold of London. › Here be pirates? Stephen Bush is political editor of the New Statesman. His daily briefing, Morning Call, provides a quick and essential guide to domestic and global politics. He also co-hosts the New Statesman podcast. Subscribe For more great writing from our award-winning journalists subscribe for just £1 per month!