Hi Again,
Thanks track_mr2, your response is appreciated.
This happened Monday night, so I went to work in wife's car again on Tuesday, & rang RAC for roadside assistance.
We are members, & probably average well less than one call a year, so figured why not.
When the patrolman arrived, I spoke to him on the 'phone to tell him about the problem.
His immediate response was, you have flooded it.
Because of starting & only running it for less than a minute to drive it into the garage from the driveway, & then later trying to start again.
Sure enough when I got home in the evening my wife said that was it, & it was fixed.
I haven't flooded an engine in many years, & don't know what the RAC man did to fix it.
Maybe he did nothing, because the fuel had already vapourised since my trying to start the night before.
I will google to see what I can find.
I was surprised, I thought something had died.