Booming demand for Eurostar’s new High Speed 1 services from St Pancras to Paris and Brussels, has led to expansion work at Gard du Nord.

The £5.8bn ($11.4bn) track covering the 68mi (109km) from London to Folkestone has slashed journey times to the French and Belgian capitals to just 2h15min and 1h51min respectively, resulting in high traffic numbers.

Specifically, the Gare du Nord upgrade will aim to ease bottlenecks – particularly at peak times – with new check-in gates and increased border control capacity, as well as an additional X-ray machine.

The new check-in gates will also accept bar-code ticketing, which Eurostar is trialling later this year.

Most of the building work will be undertaken at night and is slated for a summer finish. Eurostar says it is confident trains will still depart on time, but is nonetheless advising passengers to allow 5-10min extra at check-in.

In a separate development, Eurostar says it has opened the first phase of its business lounge at St Pancras. Despite the station costing some £800m, the lounge was not ready in time for the 14 November start date last year, with business travellers only able to use facilities in Paris and Brussels.

The delay has partly been caused by the fact that St Pancras is a Grade 1 listed building, but the initial opening will see the ground floor level feature the usual business facilities such as internet, complimentary newspapers, snacks and drinks.

Work is expected to complete on the second level of the lounge by this spring.