Punches were reportedly thrown as frustrated passengers pushed and shoved to board trains at East Croydon station after overrunning engineering works caused further delays on the first day of the RMT union’s strike.

Southern services were already reduced by more than a third because of a three-day walkout by members of the Rail, Maritime and Transport (RMT) union.

But overrunning engineering work between Brighton and Gatwick Airport meant trains were cancelled or delayed by up to an hour.

The fresh disruption caused chaos at stations including Brighton and was expected to continue until mid-morning.

Southern were not able to run trains between Haywoods Heath and Three Bridges until about 7.20am, creating a backlog of services.

A Southern spokesman said: “That had a huge impact on the train service and the number of trains arriving at East Croydon.

“We put queuing systems in place at East Croydon as we had to cancel a large number of trains and other trains had to run with fewer carriages as the trains and drivers were out of position.”

Accounts assistant Ellie Odurny said she was lucky to board a train once she got to the platform, but faced chaotic scenes at the station this morning.

She added: “It was pretty chaotic. They’d closed the gates because of platform overcrowding but were opening them intermittently and trying to direct people to specific platforms.

"It wasn’t very organised and people were getting angry when some gates were opened but others weren’t.

“There was a lot of pushing and shoving and some passengers were becoming quite vocal at the staff and rough with one another in their attempts to get to an open gate.”

The Southern spokesman added: “We do apologise sincerely to passengers affected and we do urge them to claim compensation if delayed by 30 minutes or more.

“People found it frustrating and it is particularly frustrating that it happened on a day when passengers were suffering a limited service already due to the strike action.”

Network Rail’s chief operating officer for the South East, Andy Derbyshire, said: “I'm really sorry for the unnecessary disruption to the passengers on the Brighton mainline this morning.

“As part of our ongoing track and signalling improvement work, we were undertaking track work in the Balcombe tunnel area last night. One of our heavy engineering machines suffered a break down late into the works, causing the delay to opening the line this morning.”

The union and the company continued to blame each other for the long-running dispute.

Charles Horton, chief executive of Southern's owner, Govia Thameslink Railway, said the changes to conductors' jobs were going ahead so the reasons for the strike "have ended".

RMT general secretary Mick Cash accused Southern of "peddling lies".

Southern's passengers took to social media to express their anger at the new delays, questioning why engineering work had been scheduled the night before a strike.

One tweeted: "Total chaos this morning, no trains at all to London due to over running engineering works combined with a strike."

Another said he had spent £50 on a taxi to get to work.

Mr Horton said he was "incredibly sorry" for the "months of misery" Southern passengers have endured.