Details of plans to electrify part of the railway and create hundreds of jobs were set to be announced by the Scottish Government.
Transport minister Keith Brown was expected to unveil the Edinburgh-Glasgow Improvement Programme (EGIP) during a visit to Glasgow Queen Street station today.
EGIP aims to connect services with Edinburgh airport via a gateway station under development at Haymarket in the city.
The scheme aims to deliver more reliable trains with more capacity to run between the cities, via Falkirk High.
Queen Street station will become a “world-class integrated transport hub”, the minister is expected to say.
Progress on plans for the electrification of Cumbernauld line services is also likely to be confirmed as being on target, in what is described as a boost for the Glasgow Commonwealth Games in 2014.