East Midlands Railway reintroduces services cut due to Omicron
Staff shortages caused by the strain led to widespread cuts to timetables.
Two train operators are ramping up services to meet growing demand for rail travel.
Avanti West Coast (AWC) and East Midlands Railway (EMR) are becoming the latest firms to reintroduce services cut in December and January due to the Omicron coronavirus variant.
Staff shortages caused by the strain led to widespread cuts to timetables to reduce short-notice cancellations.
But as more passengers return to the network, the frequency of AWC's London Euston trains to and from Manchester and Birmingham will be doubled from Monday.
North Wales and Chester will get a second daily service to and from the capital.
AWC, which runs trains on the West Coast Main Line, will make further additions to its timetables on May 15.
Managing director Phil Whittingham said: "As Covid restrictions are eased and people are returning to rail, we are pleased to announce a phased increase in service levels in line with demand.
"Avanti West Coast remains committed to supporting the ongoing recovery of our economy and the communities we serve, whilst enabling our customers to travel with confidence.
"We will continue to monitor demand and work with governments and industry partners to ensure we strike the right balance between connectivity and value for money for taxpayers."
The UK, Scottish and Welsh governments have taken over the financial liabilities of franchised operators during the pandemic.
EMR has reintroduced 33 regional Sunday services on routes such as Crewe-Derby, Nottingham-Matlock and Lincoln-Newark Northgate.
The operator will also reinstate its full intercity timetable from Monday, boosting services to and from London St Pancras for Derby, Nottingham and Sheffield.
EMR said the increases are possible because of "steady improvements" in the number of Covid-related staff absences, and the resolution of a long-running dispute with the Rail, Maritime and Transport union over senior conductors.
Paul Barnfield, the rail's firm's operations director, said: "We are pleased to be able to reintroduce services to our network from this weekend.
"This is a positive step in the right direction and is made possible by the continued decline in Covid-related staff absences and the resolution of industrial disputes."
Several other operators have increased timetables in recent weeks, including South Western Railway, London North Eastern Railway and ScotRail.
Latest provisional Department for Transport figures show the number of journeys made on Britain's railways is at around 70% of pre-pandemic levels.