Rail staff plan to stage a 24-hour strike in a row over pay, threatening chaos for passengers travelling on Bank Holiday Monday and commuters returning to work the next day.

Members of the Rail, Maritime and Transport union and the Transport Salaried Staffs Association will walkout from 5pm on Monday (May 25).

But what will this mean for you? Read our guide to the planned strike.

Related story: Do you commute with South West Trains? It could be worse - you could be with Southern

What information have the main operators for south west London given, so far?

Southern said its services would be severely impacted on Monday (May 25) and Tuesday (May 26) should the strike go ahead.

It said special arrangements were being put in place to ensure those who already have tickets were not disadvantaged.

Southern said it planned to add more details about the services it will run on its website tomorrow.

South West Trains also said more information would be available on Network Rail's website the afternoon of Thursday 21 May onwards.

But it said full timetables for May 25 and 26 were only expected to be available from Saturday, May 21 onwards.

Which other routes are affected?

London Overground, London Underground, South Eastern, Thameslink, Abellio, Greater Anglia, Arriva Trains Wales, c2c, Caledonian Sleeper, Chiltern Railways, CrossCountry, East Midlands Trains, Eurostar, First Great Western, First Hull Trains, First TransPennine Express, Gatwick Express, Grand Central, Great Northern, Heathrow Connect, Heathrow Express, Island Line, London Midland, Merseyrail, Northern Rail, ScotRail, Stansted Express, Virgin Trains and Virgin Trains East Coast.

What if I’ve already bought a ticket?

If you’ve already bought a ticket to travel, you may be entitled to a refund depending on your train company.

If you have a valid Anytime, Off-Peak, Super Off-Peak ticket valid for travel on Monday or Tuesday you can use your ticket to travel on Sunday (May 24) or Wednesday (May 27).

And if you have purchased an Advance ticket, it is possible you can travel at the same time as is listed on your ticket on Sunday or Wednesday.

For more details, check the National Rail website or directly with your rail operator.

What are my other travel options?

Bus routes will be running as normal but roads are likely to be congested and it is advised passengers leave extra time for their journey.

Full details of amended train timetables and which services will run, are expected to be available from train operators by Saturday, with "overviews and summaries" available from tomorrow.

How likely is it the strike will be called off?

Earlier, Network Rail (NR) urged train passengers to be prepared for the strike by workers as talks aimed at ending a pay row entered their third day.

The company said it could not bank on unions calling off the planned 24 hour walkout.

The two sides were continuing to hold talks at the conciliation service Acas, and NR said its negotiators will be available into the weekend if necessary to try to head off a strike.

Chief executive Mark Carne said: "We are continuing to talk with the unions and we believe there is a settlement to be had.

“I sincerely hope we can reach one and my team will be available all week, and into the weekend if necessary, to find a deal to prevent strike action.

"From the very start of negotiations we made clear that we want to reward our staff for the incredible job they do, but that any pay rise needs to be linked to smarter, more effective ways of working.

"We can't bank on the unions calling off the strike, so we are now concluding our contingency plans so passengers can make decisions about their journeys.

"If the strike goes ahead, it's important that people check before travelling and are aware of the special measures put in place by train operators for people who have already booked tickets."

Why have union members voted for strike action?

Members of The Rail, Maritime and Transport union and the Transport Salaried Staffs Association (TSSA) voted in favour of strike action after rejecting a four-year pay deal of £500 followed by three years of rises in line with RPI inflation.

The RMT said it has rejected the latest NR pay proposals as falling "well short" of what is required to maintain the living standards, job security and working conditions for nearly 16,000 staff across NR operations and maintenance.

NR is issuing a legal challenge to the TSSA, saying there are "numerous defects" in its ballot.

No court hearing has yet been held, and NR is not taking any action against the RMT.