This hoody was spotted down a graffiti-daubed alleyway in Twickenham today.

But in fact it was none other than London Mayor Boris Johnson getting stuck in with his roller to clean up vandals’ graffiti “tags” in Beauchamp Road.

He visited armed with a pot of paint as he launched a new mobile phone application for reporting “grime crime”.

He told the Richmond and Twickenham Times, which he praised as a “great newspaper”, that the technology would help Richmond Council save money in its fight against flytippers and vandals.

He said: “Richmond and Twickenham are very lucky, they have low crime and generally speaking, compared to other great urban centres like Rome and New York, they have very little graffiti or litter.

“But what there is needs to be removed.”

Mr Johnson was also greeted by dozens of well-wishers as he gave his seal of approval to a “beautiful” Twickenham Riverside development.

The London Mayor congratulated campaigners for fighting to keep the land open to the public.

He visited the Sunshine cafe and chatted to visitors in the new Jubilee Gardens, where Richmond Music Trust's jazz band played hits in the sunshine.

He told visitors: “What you are doing here with this fantastic riverside scheme is so important, and so important for what we are doing in London.”