High-speed rail links to the north could leave Bristol and the South West trailing when it comes to attracting investors as well as jeopardise funding on the network, MPs have warned.

Transport Secretary Lord Adonis yesterday announced plans for a new high-speed rail (HSR) network, known as High Speed Two, that would mean super-fast links from London to northern cities via Birmingham.

It would also include connecting the Great Western line to a new station between Paddington and Heathrow, allowing passengers to avoid going into London to make connections to HSR, Heathrow airport and the new Crossrail link, which provides faster services across the capital.

Lord Adonis also re-confirmed his commitment to electrification and additional rolling stock for the Great Western Main Line.

But the powerful Commons Transport committee has raised concerns that the £30 billion needed for new HSR lines may detract from much-needed investment on the existing "classic" rail network and the areas not served could potentially suffer competitive disadvantages.

That was echoed by MPs on the Commons South West committee, who warned faster journeys times and improved access to the north could disadvantage their region.

"If HSR connects the Midlands and North West regions to Heathrow, there is a risk that the South West may fall further behind the rest of England in relative journey times and access to markets," the committee said.

The South West Regional Development Agency has launched a campaign for an HSR line from London to Bristol and the rest of the region, and formed an action group to push the case.

It claims HSR would reduce the journey time from London to Bristol to about 60 minutes, bringing significant economic benefits.

While it backs the programme of electrification of the Great Western Main Line from London to Bristol in 2016 it will not achieve HSR speeds, it adds.

The Government came under pressure from MPs in the Commons yesterday to ensure Bristol does not lose out.

Lib Dem David Heath said: "I'm sure having a high-speed rail service will greatly benefit the regions it will serve, but I hope ministers will remember that there is a very big part of the country west of Reading which desperately needs good communications too.

"The electrification of the London-Bristol line is good news, but I want to be sure that funds are not diverted yet again to pay for the north-south links.

"Once upon a time we led the world in rail travel. The Great Western Railway was 'God's Wonderful Railway'. It certainly isn't now, and if we want to compete with other parts of the country and other regions of Europe, we need to be properly connected."