A News & Star investigation found the cheapest fare available is £97, and that has to be booked two months in advance.

Virgin spokesman Ken Gibbs said: “We are grateful to the News & Star for pointing this out.

“We’re not intending to deceive people by quoting £87, that’s not our intention at all. If we misled it was unintentional and we gave the fare in good faith.”

A journey to Paris or Brussels involves taking a Virgin train to London Euston then switching to a Eurostar service from the new terminal at St Pancras next door.

Although Virgin is promoting a through ticket, the fare is arrived at by adding together separate fares for the Virgin and Eurostar legs.

The £87 figure is calculated by aggregating the cheapest Virgin and Eurostar fares.

However, the cheapest Virgin tickets apply only to trains leaving Carlisle after 12.45pm.

This would mean an onward journey from London during the peak early-evening period when the cheapest Eurostar tickets are unlikely to be sold.

Mr Gibbs believes an £87 fare may become available at weekends from May when engineering work on the West Coast Main Line stops.

At present it is impossible to book through tickets to Europe at weekends because of the West Coast Main Line is partially closed.

Mr Gibbs added: “We believe this is a short-term issue.

“There are currently no weekend trains on Virgin and there is pent up demand on Eurostar because they have only just resumed a normal service [following a fire in the Channel Tunnel].

“These two things in combination make it harder to find cheap tickets.”

A new high-speed link from St Pancras to the Channel Tunnel means that through journeys from Carlisle to Brussels or Paris are possible in a little over six hours.

Tickets can be booked online at www.eurostar.com or by phone on 08705 186186.

They are not available from station booking offices.

The price includes a transfer from Euston to St Pancras on London Underground.

Craig Johnston, a Carlisle-based executive member of the RMT rail union, says the tickets should be sold at stations. “Once again, Virgin have been caught out advertising something that isn’t really available.”

“Virgin spin a yarn. Now the wheels are coming off the spin machine.”

Carlisle MP Eric Martlew was also critical of Virgin’s pricing policies and accused it of “carelessness” in promoting a non-existent fare.

He said: “There needs to be greater transparency.“People need to be able to see a price list so they know exactly what their fare will be.”