Londoners don't have a Mayor any more, they have Boris Johnson MP

The people Boris was originally elected to serve have become victims of his rampant ambition and dwindling focus

Boris Johnson arrives at No. 10 after becoming an MP in the general election (PA)

It’s no secret that Boris Johnson harbours ambitions far beyond his City Hall office, and even his new Parliamentary one.

However, for many Londoners, the image of him strolling up Downing Street earlier this week will have been an oddly disturbing spectacle, and not only because they fear losing their Mayor to Westminster. Those who have experienced his mayoralty first-hand know that his publicity-hungry and work-shy style often leaves a lot to be desired.

After only three days as an MP, the Mayor swanned in to City Hall on Monday gone 2pm, and defiantly told journalists he was definitely not a part-time mayor. The irony that half the working day was already gone was clearly lost.

Although his poor time-keeping is just the beginning of the problem. Boris has already resigned his posts on the London Legacy Development Corporation – which leads the way on post-Olympic regeneration – and as Chair of the Old Oak Common mayoral development zone. Until last week this was one of his flagship regeneration projects, and is expected to produce many new homes. However, both of these important mayoral duties will now be overseen by unelected bureaucrats – a theme which is likely to grow in coming months.

Ambition can be a great thing for politicians, yet with Boris we've seen what happens when it becomes the sole focus. Ever since he announced last summer that he wanted to return to the Commons, more and more time has been spent out of London securing his future and less on his duties as Mayor. Campaign tours, foreign trips and photo-ops have increasingly replaced governing, policy and decision making.

Although it’s not just his lack of interest which has irked Londoners. Where bluster doesn’t cut it, Boris has increasingly resorted to drastic U-turns. Take the controversial Garden Bridge; originally meant to cost Londoners £4m and now earmarked to receive at least £60m of taxpayer cash.

When quizzed, Boris categorically ruled out spending any public money on maintenance and running costs. Days after his public pledge, it was revealed he had actually underwritten the whole £3.5m a year operating budget, promising to stump up the cash every year if the Bridge Trust failed to raise enough money themselves.

This Laissez-faire approach to the details of the job is something Londoners have started to notice. When David Cameron announced he would not seek a third term as Prime Minister, polling found that Londoners had the lowest opinion of the Boris' prime ministerial abilities. Only 20 per cent said he would be their choice as successor. And it's actually far lower than in other parts of the country.

That’s not a big surprise. After years of headline-grabbing announcements, the mediocre reality has sunk into the public psyche and expectations have dropped. Did anyone truly believe Boris’ plans to put the North Circular in underground tunnels at a cost exceeding HS2? Of course not, it’s just Boris. Acceptance has set in.

Worries about the Mayor’s absenteeism are only going to become more pronounced as we enter his lame duck year and he sets his sights on the next big job. With City Hall set for 12 months of drift, the Londoners Boris was elected to serve have now become victims of his rampant ambition and dwindling focus. Olympic regeneration and the housing crisis? Who cares, Boris seems to be saying: they can wait until I'm gone.

Val Shawcross is the Labour London Assembly Member for Lambeth and Southwark and Deputy Leader of the London Assembly Labour Group.