I can now say how we did it, because all parties with a right to know have been informed.
The man in deperation last night did call a 'certain other rescue'. He was told the kindest thing to do was PTS his mother's cats.
When he told me this morning, I called Caroline, our welfare officer, as it is ultimately she who says which cats we admit - although I knew we were packed full.
Caroline then told a few of our fosterers this man's story. A very kind lady fosterer called Sue roped in her daughter as a temporary fosterer to take over her present foster case, and Sue will have these 2 until decks are cleared.
I think the folks here involved felt that it comes to us all and we want our cats taken proper care of after we go. We realised this man was desperate to do right by his mum's beloved cats and was genuine. And of course it is so near Christmas and he must have felt his world was ending. When I told him we could take his cats, he cried with relief. I must confess I had a cry too.
He said his mother can now rest in peace.
So... we are now officially extremely packed with cats and very definitely closed until further rehomings happen, which probably means until after Christmas now.
But there was no way I was going to abandon this man.