The bus services run seven-days-a-week

The iconic buses, which have served London since the 50s, are being used on parts of routes 9 and 15.

Taking in the Royal Albert Hall and Trafalgar Square, they will run every 15 minutes, seven days a week.

Routemasters have been withdrawn from regular service - the 159 route will cease on 9 December - and replaced with double-decker and bendy buses.

'Criticism'

Unveiled on Monday, the vehicles have been repainted in their 1960s livery, complete with the London Transport logo and original cream stripe across the side.

Route 15 will run from Trafalgar Square to Tower Hill, via Fleet Street, while the number 9 will start at Royal Albert Hall, end in Aldwych, and take in Knightsbridge and Piccadilly.

The new bus tours came under criticism from London Liberal Democrats in September for missing some of the city's most famous landmarks such as Big Ben and Buckingham Palace.

Transport for London (TfL) said the routes shadow existing ones, to allow for disabled access, and take in a number of attractions.

Existing bus passes will be accepted on the buses.