As one who works in the international market, I would say this would be harmful to our economy. For instance, if there is a contract up for grabs in another country, how are we meant to have a fair go at it unless we have our representatives there? Other countries don't have this scheme, so other companies could send their guys no problem.
That can add up to a lot of missed business.
So, companies will look to move overseas. Which will mean either a brain drain, with all our knowledge and expertise being exported, or it will mean (more likely) vast numbers of redundancies in the UK, with jobs going to other countries.
These measures only work and are only fair when EVERYONE does them. I think Bush's excuse for backing out of Kyoto, whereby developing countries are excluded, is totally just. India and China produce tonnes of pollution, why should we castrate our economy just so they can play catch-up?