'Parliamentary' trains were those enshrined in an 1844 Act of Parliament that made provision for very cheap rail travel on a very limited number of services for the working classes to travel into towns and cities to their jobs.
Nowadays it refers to those trains that often only run once a week, and often in one timetabled direction only, to save rail operators the expense of formally closing a railway line.
Wonkypedia explains it quite well.
"I am not expendable, I'm not stupid and I'm not going outside." (with apologies)
Rory Stewart's said schools should close. I don't know if that's sensible at this stage or not, but it's quite effective politically, I think. Stewart has some flair, and could run Bailey close. London could be to the Tories what California is to Republicans now.
Looking at the results from 2016, Goldsmith was competitive in more boroughs than I would think from here. He narrowly won Hammersmith and Fulham, for instance. They were nowhere near winning the combined constituencies in the 2019 General Election, when it was Johnson v Jez. Bailey isn't winning that v Sadiq.
Goldsmith also won Croydon on first choices in 2016 narrowly (though Khan won when you include second choices). Looking at 2019, Labour are out of sight with votes in Croydon North, win Croydon Central fairly easily and even losing Croydon South by 12,000 keeps them massively ahead.