Can i sell certain brand names om my web page without their consent, ie can i sell Gap clothes or other brand names (some of which are not available in the UK) ?

Can i state (using Gap as an example) they are made by Gap, and can i leave the Gap tags in them etc Or by law am i not able to do this? I have asked Trading Standards but they are taking Ages to get back to me.

Any help would be fab, thanks liz.