DEFRA have a great deal of information on bovine TB, including the reports from the Independant Scientific Group following the Randomised Badger Cull Trial. The latest statistics on bovine TB can be found here.
The Farmer's Guardian have a section devoted to bovine TB. While often pro-cull, this site has carried articles on both sides of the debate. In particular the articles "TB: The science behind the decisions" and "Evaluating badger proofing with biosecurity trial" are well worth while reading.
This is Roscoe Young's thesis for his Journalism degree on the topic of the Badger Cull
Cull Watch is a powerful campaigning tool, with the main focus on frankly publicising the reality of the badger cull. It makes information about the cull available to the public.It also offers legal and peaceful support to landowners when faced with visits from WAG contractors. It aims to directly publicise the events in West Wales as they unfold, through a completely law-abiding programme of reportage. When the full scale of the cruelty is known, citizens of Wales and beyond can hold those responsible to account via voting and consumer choices. Support to pro-badger landowners is also available in the form of a physical presence, capable of witnessing and recording the actions of WAG’s anonymous contractors. The presence of cull monitors will also serve as a deterrent to further illegal cruelty which could occur during badger trapping and killing".
The Badger Trust is one of the leading groups defending badgers in the UK.
The Wildlife Trust of South and West Wales also opposes the cull, and owns land in the probable IAPA area, such as the Welsh Wildlife Centre in the Teifi valley.
BovineTB.co.uk is a comprehensive site, including a public forum, questioning the current response to Bovine TB.
Back Off Badgers is the RSPCA's campaign against badger culling.
Badger Watch Dyfed is a local badger interest group, affiliated to the Badger Trust.
Black and White is a site devoted to campaigning against the cull, and has an on-line petition or you can download the petition form to print out.
The RSPCA have a Badger section on their website.
Badgers and TB gives the point of view of one eminent badger expert, Martin Hancox, with some excellent explanations of the science.
The Newport Area Environment Group, based in the IAPA, opposes the cull
There are a couple of Facebook pages opposed to the cull, such as ANTI BADGER CULL here.
The Welsh Assembly's website has a section on bovine TB here
The NFU has been one of the more vocal proponents of a badger cull.