Eurostar has said there will be almost no services between the UK and Brussels on Monday because of industrial action set to hit Belgium's rail network.
The rail passenger operator will run a revised service between Lille and the UK, plus a "limited" coach service between Lille and Brussels.
However it urged passengers planning to travel between the UK and Belgium to postpone their journey if possible.
Eurostar services between the UK and Paris will operate normally it added.
The industrial action meant it was unlikely there would be any high-speed rail connections from Brussels to destinations in France, the Netherlands and Germany, Eurostar said.
The 24-hour strike is due to begin at 2100 (BST) on Sunday and will end at 2100 (BST) on Monday.
A Sunday service due to leave London to Brussels at 1934 has been brought forward to 1727 so that it arrives before the Belgian rail network closes.
And on Monday, the 1934 departure from London to Brussels is due to operate as scheduled.