If the Labour leadership contest has felt long, it has been a mere 100m sprint compared to the marathon of the party’s London Mayoral selection, which has to some extent been going on almost since the moment Boris Johnson returned to City Hall in May 2012.

Today that epic journey has at last come to its conclusion with Tooting MP Sadiq Khan overcoming Tessa Jowell in the fifth and final round of voting.

With 59% to Jowell’s 41%, the result was in the end not so close as many had anticipated, and it most certainly did not prove to be the coronation for Olympic bid hero Jowell some predicted months ago. Khan led in every round of voting and has earned a clear mandate from London Labour’s combined selectorate of members, affiliates and registered supporters.

When focusing only on full members however, a slightly different picture emerges, in which Jowell led in every round but the last. This seems to point to something of a ‘Corbyn effect’ with Khan performing very well among the newly signed up registered supporters and reaping the benefits of the endorsements he received from unions such as Unite and GMB – the same groups that have helped to inject such momentum into the ‘Jez We Can’ campaign.

However Khan himself is no Corbynite. Yes, he was one of those who nominated the Islington North MP to ‘broaden the debate’, and his campaign shrewdly avoided any confrontation with Corbyn, but he has today revealed that he backed Andy Burnham for leader. Khan was Ed Miliband’s campaign manager in 2010 and he belongs much more to the ‘soft left’ of the party than the hard left represented by Corbyn.

However with Jowell at times pigeonholed as the ‘Blairite’ candidate, and Corbyn-ally Diane Abbott failing to ever really break into the two-horse race at the front of the pack, Khan was the candidate who ultimately benefitted most from Corbynmania and Labour’s new voting system.

Nevertheless, it would be unfair and inaccurate to suggest that Khan won only because of the Corbyn effect. He has been a significant figure within the London Labour Party over the past five years as Shadow Minister for London and co-ordinator for Labour’s General Election campaign in London. In the latter role he enjoyed significant success in May, with Labour performing better in London than the rest of the country and making a total of 7 gains with an increase of 7.1% in the party’s share of the vote, bucking the national trend. Under Khan’s watch the party also gained five councils and had its best ever European election performance in London in 2014.

These successes undoubtedly bolstered his credibility and enabled him to forge crucial links in the capital which have stood him in good stead for the Mayoral selection, even though he was a comparatively late entrant to the race compared with the likes of Jowell and fourth-placed David Lammy.

So what will the Khan candidacy look like in the 2016 Mayoral election?

It is clear that he already has one eye on his likely Tory opponent in that contest, Zac Goldsmith. During the Labour selection, Khan performed a u-turn in his support for Heathrow expansion, coming out against a third runway at Heathrow in favour of a second at Gatwick. This earned him some mocking from his Labour opponents, but was almost certainly a calculated move to ensure vocal anti-Heathrow expansion Goldsmith could not outflank Khan on this issue. Amongst other measures to bolster his green credentials Khan has also signalled his support for the pedestriansiation of Oxford Street.

House-building will be another priority, and he has signalled that he would have a new homes team reporting directly to him at City Hall and that he will “personally oversee the bringing forward of land, the unlocking of development, and the building of thousands of homes.” He would bring in a 50% affordable housing target for any new development. For those in the private rented sector, Khan wants the Mayor to be granted the powers to implement rent caps.

Further devolution to City Hall is likely to be a recurring theme of his candidacy with Khan also seeking new powers over skills and further education. He has also vowed to use the Mayor’s procurement powers to boost apprenticeships and promote the London Living Wage. A four year freeze on public transport fares would also be on the agenda.

But for any of this to come to fruition, Khan has to win first. Will he?

For Tessa Jowell, her trump card seemed to be polling which indicated that she alone of Labour’s candidates would clearly prevail even against a Goldsmith candidacy. The same polls indicated a far closer race between Khan and Goldsmith. (Though of course we should wait and see if Zac is indeed the Tory candidate – in the current climate of political surprises, nothing should be taken for granted!)

For Sadiq Khan, the hard work starts now.