Strict new European Union border rules threaten to spell the end of “turn up and go” Eurostar travel.

All non-EU passport holders will be required to have their fingerprints and picture taken once the new entry-exit system (EES) is launched on October 6.

Passengers travelling on Eurostar from St Pancras will be expected to ­arrive at the station in central London at least two hours before their train ­departs for the extra formalities to be carried out. At present the operator ­advises ­getting there at least 90 minutes before departure. Before Brexit, passengers could turn up with as little as 40 minutes to spare.

Work is under way to install 49 entry-exit system kiosks at St Pancras. On ­arrival at the station, holders of non-EU passports will be directed to the ­terminals to complete the additional checks before they can proceed to the existing check-in.

The finger and picture biometrics will be captured on a passenger’s first visit to the bloc after October 6 and one of the identifiers will be ­verified on each subsequent entry and exit. Captured details will be stored for three years.

Most passengers will use kiosks near the main entrance on the ground floor of St Pancras, although there will be an overflow area on the mezzanine level. Business and disabled travellers will have a dedicated area near check-in. Preparing to implement the new entry requirements is understood to have cost Eurostar, which operates trains between the England and France, ­Belgium and the Netherlands, more than €10 million.

Holidaymakers are being warned to expect long delays when the system is launched. Implementing it is especially tricky at St Pancras, where space is constrained and where border controls are juxtaposed with French immigration formalities carried out on UK land.

The new system had been due to be launched in May last year, but it was ­delayed by EU officials because of IT problems. It was also the subject of ­intense lobbying by French ministers, who did not want the bureaucratic scheme to be in place during the ­Olympic Games this summer.

A spokeswoman for Eurostar said: “We are working closely with the authorities in the UK and EU member states to prepare for the arrival of EES. Our aim is to minimise the impact on our customers to ensure the smoothest possible travel experience and the ­detailed work required to achieve this has been under way for some time.”

The EU describes EES as an “automated IT system for registering non-EU nationals travelling for a short stay each time they cross the external borders of European countries”. It is designed to make the bloc’s border more secure in the face of terrorist threats.

Separately, HS1, the rail infrastructure operator that runs St Pancras and the high-speed line to the Channel Tunnel, has begun work on a project to increase capacity at the station. It is seeking to appoint designers to carry out a capacity enhancement study ­focusing on the terminus. The work, separate to the introduction of the entry-exit system, is aimed at increasing international passenger capacity.

A rail industry source said: “St Pancras is a seriously congested station when it comes to international departures and Brexit has had a serious impact on this. Queues at peak time are longer than they were prior to Brexit because the processing time of each passenger [at the French border] takes longer. Add in the EES and the days of the ‘turn up and go’ model really are over. But it’s credit to Eurostar how much they are doing to prepare.”

There are also fears of queues in Kent for car passengers crossing the Channel when the new system is launched.

Doug Bannister, chief executive of the Port of Dover, previously has said that the scheme could cause “significant and continued disruption for a very long time”. He warned of the risk of passengers getting out of their cars in “live lanes” at the French border.