A strike by workers at one of the UK’s biggest train operators was being “solidly supported” on Tuesday, causing disruption for tens of thousands of passengers.

Members of the Rail, Maritime and Transport union on South Western Railway will be on strike for five days in the long-running dispute over guards on trains.

Commuters into London Waterloo station were among passengers affected, as well as race goers heading to Royal Ascot. Buses replaced trains on some routes.

Racegoers heading to Royal Ascot
Racegoers heading to Royal Ascot are affected (Chris Young/PA)

RMT general secretary Mick Cash said: “RMT members are standing rock solid again this morning on South Western Railway in the long-running fight for safety, security and access on our trains while the private train company sends out the signal that it is prepared to gamble with their passengers well-being in the name of profit.

“RMT has campaigned relentlessly for the principle of putting safety on the railway first and the current stalemate over the safety-critical role of the guard on SWR trains cannot be allowed to drag on any longer.

“Our members have been left with no choice but to go ahead with strike action throughout this week. They are angry and frustrated that despite suspending action in good faith, and entering into talks in a positive and constructive manner, South Western Railway have dragged their heels and failed to bolt down an agreement that matches up to our expectations on the guard guarantee.

“We thank the public for their continuing support and understanding that this dispute is all about safety, access and passenger service on Britain’s increasingly violent and dangerous railways.”

There were chaotic scenes at some stations, with long queues and packed platforms.

One of the biggest queues was at Surbiton, where some passengers said they were told to return after 11am because so many people were trying to get into the station.

Passengers between Egham and Staines faced further delays because of a swan on the railway line.

Thousands of commuters shared their experiences of the travel disruption on social media, with footage showing queues spilling out of Surbiton station in south-west London, and a long way down the street.

“It felt very unorganised, one person trying to deal with everyone’s queries and he didn’t seem to have a straight answer,” said 29-year-old Adam Neal-Jones, who posted a video to Twitter.

“The queue was surprisingly orderly and people were joining it with little qualm in a very British way.

“A lot of people stood about quite unsure if they should attempt a bus or to get to a different station.

“I think surprise was the general mood as it seemed to be fine according to national rail app and we had been told there would be minimal disruption.”

Speaking at 8.45am, Mr Neal-Jones said he was told 11am was the earliest he could expect to board a train.

A South Western Railway spokesman said: “We are sorry that customers faced long queues at Surbiton station this morning. While we are doing all we can to keep passengers moving during this unnecessary industrial action, Surbiton station is one of our busiest stations and we need to keep passengers safe by controlling access to the platforms.

“Passengers are strongly advised to avoid busy peak periods and travel on earlier or later trains because of the reduction in services at key stations like Surbiton.

“We are looking to see if we can improve the number of services calling at Surbiton station in order to minimise further disruption during this strike action.”