Thousands of train passengers will suffer major disruption this weekend due to no direct services between London and Scotland.
The cancellations are a result of engineering works on two major routes being carried out by Network Rail.
The Government-owned company said sections of both the East Coast and West Coast main lines on Saturday and Sunday must close as a result of a “congested work programme”.
Journeys between London and Scotland will be significantly slower and require at least one change.
Watchdog Transport Focus said this situation “should not happen” and said one line should be kept open to ensure passengers in Scotland and the north of England still have direct access to London.
In a current itinerary suggested by Network Rail Enquiries, journeys between London and Edinburgh on Saturday morning will involve three trains and one bus.
The journey is expected to take a total of six hours and 12 minutes, nearly two hours longer than the normal direct service.
The West Coast main line runs between London and Glasgow, with branches to Birmingham, North Wales, Liverpool, Manchester and Edinburgh.
It will be closed between Wigan North Western and Lancaster during the next three weekends and Sunday March 12 to enable track upgrades at Preston station.
Ordinarily a full service would operate on the East Coast main line, which stretches between London and Edinburgh via Peterborough; Doncaster; York and Newcastle, when engineering work is carried out on the other route.
However, there are no trains between London and St Neots, Cambridgeshire, this weekend while a new signalling system is brought into use.
Avanti West Coast, LNER and Lumo are among the operators affected by the closure.
Transport Focus chief executive Anthony Smith said: “Passengers will be disappointed to see both East and West Coast lines closed due to engineering works this coming weekend.
“This situation should not happen.
“One line should be kept open so that passengers from Scotland and the north of England have access to a direct train service to London.
“Both train operators and Network Rail must ensure that there is effective communication to support passengers.”
A Network Rail spokeswoman said: “We always try to have a direct cross-border route open, but that has not been possible on this occasion.
“The industry – both Network Rail and train operators – have looked at the alternatives, all of which cause more disruption for passengers.
“We also have a congested work programme caused by landslips, floods and strikes, severely limiting those alternatives.
“We understand the inconvenience this will cause to some of our customers and wish to reassure them that this will be a one-off.”