Watch: London cyclist has scary moment as bus cuts into cycle lane, but who was in the wrong?

Cyclist was undertaking the bus, when it drifted into mandatory cycle lane

A video of a cyclist undertaking a bus before the bus drifts into the cycle lane, almost forcing the cyclist off the road, has sparked debate on social media.

The video was posted on Facebook by Ian Croft with the title "Is this bad driving or poor cycling?", and was apparently captured during Croft's commute through south east London from Sidcup to Clapham.

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The footage shows the cyclist using a cycle lane to undertake a slow-moving bus. The cyclist makes it alongside the the bus, which then starts to move, drifting to the left into the cycle lane, forcing the cyclist to a stop.

What follows is a foul-mouthed confrontation between the cyclist and the driver, but debate about who was in the wrong has continued on social media.

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According to rule 140 of the Highway Code drivers "MUST NOT drive or park in a cycle lane marked by a solid white line", which seems to put the bus driver fairly comprehensively in the wrong.

The Highway Code is less clear on whether the cyclist should be undertaking, with a number of different rules telling motorists to look out for cyclists who may be filtering through traffic, but also warns cyclists to pay particular attention to long vehicles, and "not be tempted to ride in the space between them and the kerb".