Oven Cable Extension?

Hi all. Hoping someone can offer me a little advice.

I have recently purchased a new electric Hotpoint SA2540HIX Single Oven. This has a moulded 13amp plug at the end of the cable, the other end of which disappears into the back of the oven itself and isn't accessible (probably for a good reason!)

Unfortunately, this supplied cable is stupidly short and doesn't extend long enough to fit into the existing plug socket that has been used absolutely fine for the two previous ovens. It's not practical to move this socket easily.

Is there a way I can safely easily extend the cable (maybe cutting off the plug and wiring it into some kind of junction box to add a couple of inches before wiring the plug back on the other end?). It just needs to be around a foot longer than it actually is.

Any advice would be appreciated. Thanks in advance!