Matt Prior has suggested he would welcome England and Australian umpires officiating in Ashes Tests in an attempt to eradicate the errors that have marred the Investec Ashes series.

England have become increasingly frustrated by the unpredictability of the umpiring in the series. While they are sympathetic to the on-field officials, understanding that mistakes are inevitable in such circumstances, they are less phlegmatic about mistakes after the involvement of the DRS.

The latest controversy concerned an appeal against David Warner, after England were convinced his attempted pull shot had resulted in an edge to wicketkeeper Prior. Hot Spot, which has looked an increasingly unreliable tool in this series, showed nothing, but audio replays suggested an edge. The TV umpire upheld the on-field umpire's decision of not out. Snickometer, which is not part of the DRS, also backed up England's case.

It left England "frustrated" in Prior's words, and while he remains supportive of the DRS in general, he did suggest the system may require some examination and expressed a willingness to abandon one of the founding principles of Test umpiring in recent years: that of neutrality.

"I honestly don't care where the umpires are from as long as the right decisions are made," Prior said. "I think that is the most important thing. You need to make sure that decisions are correct.

"It doesn't matter if they are Aussies or English or anybody else; all you want is the right outcome at the end of the day.

"There was disbelief [when Warner was given not out] because he hit it. That's why we referred it and when you are that sure and it is still given not out it is quite frustrating. That's why there was a bit of chat around.

"There wasn't any evidence [from Hot Spot] and that is frustrating. All you can go on from a referral point of view was how you see it. Alastair Cook and I were pretty adamant he had hit it. I think Snicko shows he did. We were right in referring it, but unfortunately it did not go our way.

"It is pretty frustrating for everyone at the moment," he said. "At no time will we ever be critical of an umpire making the wrong decision on the field. Everyone makes mistakes in a day. I know more than anyone: it all happens quickly. Everyone is looking at me for DRS decisions and it happens quickly.

"I have always said I am a big fan of the DRS. It works and it is the way forward but once you use a review you have to then get a decision right. Once it goes up to the third umpire the decision that comes out has to be the correct decision. Whether the technology needs to be looked at or how they use it, I don't know. But for the players at the moment that is the biggest frustration."

ESPNcricinfo understands that the possibility of utilising non-neutral umpires in the Ashes has been discussed, but that the Australian and English boards are reluctant to set a precedent that could result in non-neutral umpires around the world. Instead, the boards are considering inviting overseas umpires to officiate in their own domestic cricket with a view to helping them develop their skills.

At present, only four umpires - Marais Erasmus, Tony Hill, Kumar Dharmasena and Aleem Dar - are eligible to stand in Ashes series as the rest on the ICC's elite panel are from either England or Australia.

George Dobell is a senior correspondent at ESPNcricinfo