Second consecutive day of public transport strikes
Buses and trains cancelled as workers stage walkout
Widespread disruption is expected to all bus and train services in Northern Ireland for the second day in a row, as public transport workers begin their latest round of strike action.
Workers from the Unite, GMB and Siptu unions are taking industrial action again on December 22.
The UK Government has offered a financial package which includes money to settle public sector pay disputes, but it is conditional on the return of the Stormont Assembly.
Translink has apologised for disruption caused by the strikes.
A statement said: "We are disappointed with this decision by our union colleagues which will disrupt bus and rail services that so many of our passengers rely on, particularly at this busy time of the year.
"We are fully committed to enter into pay negotiations once the budget issue has been resolved.
"The budget issue, which impacts on many public sector workers, needs to be resolved at the NI Executive level."
The industrial action follows a previous one-day strike by bus and rail workers earlier this month.
Unite union general secretary Sharon Graham said: "The failure of the Secretary of State Chris Heaton-Harris to intervene and provide any pay increase has left Translink workers no alternative but to escalate industrial action.
"All too often Translink workers are on the front line of social disorder or unrest now in the midst of the worst cost-of-living crisis in a generation, they are being told to accept an 11% real-terms pay cut.
"That is completely unacceptable. They continue to have the full support of Unite in their fight."
GMB regional organiser for Translink Peter Macklin said: "At the beginning of the month, Chris Heaton-Harris was denying he had any powers to deliver a pay increase to workers then earlier this week he tabled a completely inadequate financial package which he claimed would be enough for a public sector pay increase.
"While that has been universally rejected - his actions show that he has had the power all along to intervene and address our members' pay claim."
A Northern Ireland Office spokesperson said: "It is for the relevant Northern Ireland department to make final decisions on pay policies.
"The UK Government has no authority to negotiate pay in Northern Ireland.
"The Secretary of State has invited representatives from the five largest parties in Northern Ireland to discuss how the Government will work with them to stabilise the finances of a returning Executive.
"These discussions are centred on how the UK Government can help with and support sustainability in Northern Ireland's public finances for when a Northern Ireland Executive is restored."