He's having the .co.uk domain forward to his site but his domain and business name is then clearly displayed and it's clearly his site so it's not pretending to be you or your site and it's not your business name so not illegal, it's definitely underhand, immoral and distinctly shitty.

For the .co.uk you can complain to Nominet UK and they will tell you if it's worth going through the appeals process to stop try to him doing this, give them a call as they are super-helpful people and will give you good advice, using something close to your name for the same kind of business sector could infringe Nominet's rules for domain use.

The .com does supress his business name and display the dodgy domain so that's arguably an attempt to impersonate your business but a .com is much more expensive to appeal but again worth investigating.

I can't believe what a complete wanker the guy must be to be doing this!
Regards,
Nick