best way to connect a gas hob over built in oven?

I've got an electric fan oven with a gas hob to fit in my new kitchen. The old oven plugged straight into a socket behind and to the right of it and the gas hob was connected via a flexipipe behind and on the left side of the oven. I've been told this can't he done as the heat from the oven could melt the pipe (original hob was fitted by gas safe registered 14 years ago)
I never had a problem in all the years both were in situ but I'm concerned that if a fixed copper pipe is used then it would be in more danger from the oven than a flexi pipe as metal holds heat were as the flexi won't.
I might be able to put the hob next to the cooker as opposed to over it with a bit of jigging about but space is tight.