Scottish Labour leader Kezia Dugdale launched a campaign for a rail fare freeze in Edinburgh today as signalling problems caused more disruption in Glasgow.

Ms Dugdale says the plan could save commuters up to £100 on season passes next year.

She said the freeze is needed because passengers are "fed up with expensive, overcrowded and delayed trains".

ScotRail produced a performance improvement plan in September at the request of Transport Scotland after punctuality and reliability fell below target.

Problems with the network came to a head last week when a broken-down train just outside Edinburgh Waverley caused widespread disruption.

Regulated rail fares, including season tickets, are due to rise by up to 1.9% from January.

A fare freeze could give 2017 season-ticket savings of £82.06 between Edinburgh and Glasgow,£94.57 between Glasgow and Perth and £89.40 between Edinburgh and Dundee, Labour said.

While Ms Dugdale launched the proposals at Edinburgh's Haymarket station, Labour's transport spokesman Neil Bibby was at Glasgow Central and other Labour MSPs will be campaigning across the country in the coming days.

Ms Dugdale said: "Passengers are fed up with expensive, overcrowded and delayed trains.

"They deserve a break. That is why Scottish Labour believes passengers deserve a fare freeze in 2017.

"On some commuter routes, this could save passengers nearly £100 over the course of a year.

"Nicola Sturgeon has said she will consider our proposal. Rail fares are due to rise in January, so the SNP should intervene right now to give passengers the fare freeze they deserve."

During First Minister's Questions at Holyrood on Thursday, Ms Sturgeon said the Government will consider any proposal put forward.

A Sottish Government spokeswoman said: "As the First Minister stated in Parliament on Thursday, we will consider any fully costed options that might enable us to reduce costs to passengers while still delivering our ambitious infrastructure programme.

"We want to see a vibrant, growing industry with more seats and services than ever before.

"Ministers remain focused on ensuring the best outcome for passengers - a franchise which delivers for Scotland."