Went to Tenerife on a TuiFirst Choice holiday in 2017 and flew with Monarch who went bust the day after. First Choic rep was a waste of time when we tried to find out what was happening.

Have you tried contacting Thomas Cook Mari?

I've emailed tui first will see what they say tui always used to do their own flights when we went

Thomson (Tui) and TC have been wet leasing each others planes for years, I've known people who booked a package holiday with TC and they've flown with (as it was then) Thomson.

Don't know if it's the same now, but you couldn't get into their systems to book seats etc, and API was collected at check-in.

Just found this, it might help.

https://www.thomascook.com/airlines/thomson-airways/

Sanji x

I have noted when booking with Tui that when looking for alternative flights they often show them using Easy Jet, does make business sense - one full plane rather than two half full.

Thanks someone on another forum gave me a link so I can pre book seats and can check in. Tui gave 20kg luggage allowance with this holiday so just needed seats. I just would hate to be separated.