Mon-Thurs 3 nights so not too expensive per night !
Near Westminster (or easy tube ride) as Year 12 ds has work experience with MP.
He is staying with adult dd, so ideally twin room (she will sight see whilst he is at 'work').
I'd like it to be a treat for their birthdays,but in reality budget is £300/night.
Have looked at Premier Inn but that is booked for the dates.
They will arrive and leave by train at Kings Cross.