Border Force, rail and driving test staff are resuming strike action today - but strikes by waste collection workers in Wirral have been called off after a pay offer was accepted.
Those striking on Wednesday include:
Members of the Transport Salaried Staffs' Association (TSSA) at Great Western Railway will walk out from noon to 11.59am on Thursday
West Midlands Trains will strike for 24 hours from noon until the same time on Thursday
Driving examiners from the Public and Commercial Services (PCS) Union at 71 test centres will launch a five-day strike
Border Force officers at the same union will begin a four-day strike at six airports across the UK
But more than 200 bin workers in Wirral have ended their industrial action after securing a 15% pay rise backdated to April.
Unite the union members employed by Biffa Waste Management held a week-long strike earlier this month and had planned further industrial action from today.
Union officer John McColl said: "Following renewed negotiations, an improved offer was put forward from Biffa which our members voted to accept.
"The dispute has now ended and strike action has been cancelled".
A Biffa spokeswoman said services would now resume and "any missed collections will be picked up as soon as possible".
But no such agreement to halt the strikes has been reached on the railways, with West Midlands Trains saying none of its services would be running from Wednesday morning as a result of the TSSA industrial action.
TSSA organising director Nadine Rae said the government could help end strike action if it allows employers to "freely negotiate" with others.
Asked about reports that rail union and industry bosses are "nearly there" in agreeing a pay deal, Ms Rae told BBC Radio 4's Today programme that "things have not changed since before Christmas in terms of a deal".
She added: "It's the government that needs to shift this situation and we really want them to, we know the disruption is frustrating for people."
Network Rail has told passengers to prepare for "significantly disrupted" travel into the new year amid the wave of industrial unrest.
'Strikes could be called off tomorrow'
Driving instructors, who are part of the PCS union, are also taking part in continued industrial action - walking out of test centres across Eastern England and the Midlands.
They are set to return to work on 1 January.
PCS general secretary Mark Serwotka said: "These strikes could be called off tomorrow if Rishi Sunak and Jeremy Hunt put some money on the table."
Mr Serwotka said his union's members "have been offered a pay rise of just 2% at a time when the cost-of-living crisis is above 10%".
But Downing Street today doubled down on its belief that a "fair agreement" to end strike action should not involve double-digit pay rises for workers.
A number 10 spokesperson told reporters such salary increases would "embed inflation" and said officials want to see unions hold further talks with employers to end strike action.
Border Force officers at Gatwick, Heathrow, Birmingham, Cardiff, Manchester and Glasgow airports and the port of Newhaven have also resumed strikes in the same dispute, and will return to work on New Year's Eve.
A Home Office spokesperson said passengers should expect disruption during the action, but added that staff are "working hard to ensure travellers have a safe and secure journey".
Unions trying to find ways to stage more strikes
Unions are looking at ways to stage further strikes by splitting ballots by job titles rather than holding a single vote, according to reports.
The i newspaper reported that the TSSA is poised to let different sections of its membership vote at different times in order to carry out multiple walkouts per week.
The Department for Transport has described the reports as "incredibly disappointing" and urged unions to "step back, reconsider and get back around the table".
Elsewhere, a new poll has suggested that 40% of junior doctors plan to leave the health service as soon as they can find another role.
While a third (33%) of the 4,500 junior doctors in England surveyed said they were planning to work in another country in the next year.
Pay and poor working conditions were the main reasons cited for wanting to leave, according to the British Medical Association (BMA) poll.
The BMA warned that the NHS "would not be able to cope" without two fifths of its junior doctor workforce.
It comes ahead of an industrial action ballot of some 45,000 junior doctors in England, which will open on Monday 9 January.
A spokesperson for the Department of Health and Social Care said: "Our multi-year pay deal with the British Medical Association is increasing junior doctor's pay by a cumulative 8.2% by 2023."