Travellers at the stations were told that social distancing "will not be possible" because of the volume of people on board, and those who felt "uncomfortable" should not stay on the train.
UK journalist Harriet Clugston wrote on Twitter: "Everyone of course has suitcases. People have tried to secure social distance by placing on seats but being asked to remove them by other passengers as the train is so full."
Once the new restrictions come into effect, non-essential shops, gyms, cinemas, hairdressers and bowling alleys will close for two weeks, and people will be restricted to meeting one other person from another household in an outdoor public space.
For the rest of England, the Christmas "bubble" policy - allowing up to three households to meet over the holiday period - will be severely curtailed, applying on Christmas Day only.
- additional reporting: Daily Telegraph UK