-The last time (when) they went on strike was 2001.
-Last time (when) were in London with the kids we had dinner at Amaya
I have encountered such these sentences beginning with 'the last time', and I have seen some people say that 'when' is not used or say it is OK.
Could you please tell me if 'when' is OK or not?
You can use it if the 'when' clause is parenthetical.
"We rarely eat at restaurants. The last time, when we were in London with the kids, we had dinner at Amaya."
But this refers to the last time we ate in a restaurant, not the last time we were in London.