Buses in London are getting slower, with transport chiefs blaming an "unprecedented" amount of construction work.

The monthly mean speed recorded by Transport for London (TfL) fell from 9.5mph in 2014/15 to 9.3mph during 2015/16.

The number of passengers has also fallen during that period, with 71 million fewer bus journeys made during 2015/16 than over the previous year - a 3% annual decline.

The figures were highlighted by London TravelWatch, which attributed the fall in bus passenger numbers to the decline in speed and reliability.

'Very worrying picture'

Stephen Locke, chairman of the transport watchdog, said: "This is a very worrying picture. Bus service performance has deteriorated and passengers are abandoning bus services in significant numbers.

"This decline must be tackled by TfL. In the short term a top priority is for TfL and the London boroughs (which control 80% of the roads our buses use) to extend the operational times of bus lanes, and to enforce yellow and red line controls so that bus lanes can be fully used.

"In the longer term, there is a pressing need to extend bus priorities across much larger parts of London's road network."

Passenger numbers expected to rise again

Mike Weston, TfL's director of buses, said: "We saw a small reduction in the number of people travelling on buses last year due to congestion caused by an unprecedented level of commercial development across the city and extensive action to improve road safety and layouts at many of London’s busiest junctions.

"We expect to see a return to growth in the number of people using buses following completion of a number of these projects."

London mayor Sadiq Khan recently announced plans to quadruple the number of officers clamping down on illegal cab operations in the capital.