I don't drive many miles, I work within 3 miles of home and family & friends live within 20 mins drive.

Diesel would be inappropriate for this usage.

My partner is admiant we need a diseal for this purpose as a petrol would not pull a trailer.

Your partner is talking nonsense.

Look at it this way.

You/He want to buy a used diesel and you will possibly get a car out of warranty, possibly with the awful Ford powershift gearbox. You won't know how it has been used or abused by a previous owner. A recon powershift g/box is north of £4000. DPF issues as well if diesel. and no used car aftermarket warranty is going to cover those items.

If only a trailer for camping stuff, Kia Sportage or hyundai Tuscon or even the Kuga

the first two may have some manufacturers warranty left and are probably more reliable than the Ford.

Other choices are available as well, but my firm opinion is a diesel would be totally wrong for your usage.

No issue with petrol, couple it with a decent autobox and you won't even know you are pulling a camping trailer. I used to go camping with a 90bhp Merc B class, fully loaded including a roof box and it hardly left me stranded.

Trade in value of a diesel which will be 12-15 years old in ten years is irrelevant, potential ownership costs doing continual short trips is, diesels don't like it,