Tube passengers have been urged to "check before you travel" at weekends because of an extensive programme of improvement work over coming months.

Earlier this year, London Underground announced a major increase in the level of engineering work at weekends as part of Transport for London's £10 billion investment programme.

The pace of work has increased to almost double that of last year, a momentum to be maintained for many years to come.

LU has launched a TV advertising campaign, front by its managing director Tim O'Toole, to press the message; "Check before before you travel on the Tube at weekends, and plan an alternative route or allow extra time if necessary."

TfL already targets regular commuters and weekday Tube passengers with posters and leaflets at stations, but this does not always reach weekend passengers.

Mr O'Toole said: "After decades of underinvestment, we are investing billions to improve the Tube.

"This is funding massive improvement works which means we have to close some stations and sections of lines at weekends.

"We recognise that this will inevitably cause some inconvenience to passengers but this will result in a much improved London Underground."

Improvement works include a major series of weekend closures on the Northern and Victoria lines throughout 2006.

The Waterloo & City line is closed until early September and Regent's Park and Lancaster Gate stations are closed.

In addition, Network Rail works will also mean the suspension of parts of Underground lines at times.

Before travelling at weekends, passengers are advised to check the TfL website, www.tfl.gov.uk/tubeworks; the London Travel helpline, 020 7222 1234, or on BBC Ceefax, page 436, or ITV Teletext, page 164.