Hi there - please give me some advice, I feel I'm being required to put out a misleading advert on-line.

My client - a big-name consumer brand - is about to launch their first ever on-line advertising campaign.

The offer is "Spend £X.XX in our on-line Shop and get a free [product]." It's a great offer, as the gift product is unique, very attractive and not easy to find in shops, and the whole lot gets free delivery too.

While my company is operating the offer functionality on the Shop website, the Flash banner adverts for the partner sites are being created by another agency - a large-scale advertising agency with a digital off-shoot.

Problem is, this Ad agency has produced an advert banner where the ONLY text says "Get a free [product]!". There's lots of Flash brand imagery, and a tiny asterisk which, the agency says is intended to refer to terms & conditions text BUT held on the clicked-to site, the site we manage.

We feel this is BAD user experience. It means that the first point when the user sees they have to buy to qualify for their free gift, is when they've already clicked through to the Shop site. I can see users feeling conned - a shame when the offer is actually a great one. Having the T & C's a whole site away feels wrong.

When we raised our concerns with the ad agency, they dismissed it, at one point saying "there are lots of websites out there with hooks like that, it's not a problem". The agency is very big on branding and print ads, but this wing has very little experience of on-line behaviour.

Any guidance out there? Anyone with a clear handle on the rules about potential mis-leading advertising, or good practice in on-line offers? I'd be very happy to hear from you!