Established in 2006, the NWCU is responsible for investigating crimes against wildlife in Britain. Some of the issues it deals with include; trade in endangered species, illegal taxidermy, bat and badger-related offences, illegal bird egg collecting and cruelty to wild animals.
Before Christmas, the NWCU was told a decision regarding funding would be reached by the end of January, but as yet it hasn't heard whether funding will continue - meaning the unit could close within weeks.
George Osborne’s spending review failed to confirm whether funding support would continue past March 2016. A large portion of the unit’s funding comes from the Department for Environment, Food and Rural Affairs (Defra) and the Home office.
Speaking to BBC Countryfile Magazine, Chief Inspector Martin Sims, said: "If we weren't here, clearly police forces would struggle across the UK, as, we also provide in-depth analysis and information on wildlife protection."
He added that while the NWCU has support from Scottish Natural Heritage and National Police Council that the funding is vital for the future of wildlife protection - not just in the UK, but globally, and a lack of funding would result in many wildlife crimes going undetected.
Animal welfare organisations have been expressing their concern over the impact its closure may have on wildlife.
Josh Kaile, Head of Public Affairs at World Animal Protection, said: This week marks a six week countdown until funding runs out for the NWCU. Not only is this a slap in the face to the hard-working staff in the NWCU but it makes you wonder whether our government cares at all about our wildlife.
"Just this week ministers jumped in to announce they would pledge £80,000 to safeguard Parliament’s tradition of printing laws on goatskin parchment, but they are somehow incapable of stepping in to save our vital wildlife crime police."
He added: "Without this team in place, they will basically be giving criminals free rein to poach, bait, shoot, trap, smuggle, torment and exploit British wildlife however they like."
Leader of the Green Party Caroline Lucas also tweeted her support for the NWCU, saying "Closure of National Wildlife Crime unit would be disaster - fight for funding absolutely must continue".
Nearly 10,000 people have now signed a petition calling for funding to continue for the NWCU.