England have retained the Ashes but are far from satisfied with their work yet, as they set their sights on a third consecutive series victory over Australia.

Not since 1981 have England won the Ashes three times in succession.

But as they travel today from Manchester to Durham for the start of the fourth Investec Test on Friday, Alastair Cook's team are ideally placed to complete a historic treble begun under the captaincy of Andrew Strauss.

England were indebted to the weather yesterday, after they had stumbled to a precarious 37 for three and were then spared having to bat out another 72 overs when the long-forecast rain arrived at last.

Cook and Co could therefore last night celebrate an initial job done, with a 2-0 lead intact and only two more Tests to play, but not for long before the captain retrains minds collectively on the next task.

"The first objective was to retain the Ashes. Now we want to go on and win them and we need to up our levels a little bit at Durham," Cook said.

"The goal was to retain the Ashes. Now we want to win them, either at Durham or The Oval."

"Both sides have been quite (confused) by some of the decisions that have occurred" - Alastair Cook

England have made a virtue of staying in the present under the captaincy of Cook and with Andy Flower as a steely coach, and they will be looking no further ahead initially than their next assignment at Chester-le-Street.

The prospect of their next Ashes campaign, which starts in Brisbane in November thanks to an unprecedented schedule of back-to-back series, will definitely not be up for discussion any time soon.

"We've made a conscious effort not to put the two series together," said Cook.

"When we get to Australia, we'll concentrate on trying to win them again."

By then, they may hope that the interminable decision review system controversies which have overshadowed much of this summer's series so far are a thing of the past.

Cook admits confusion has been created at Trent Bridge, Lord's and in the draw at Emirates Old Trafford too by the often contrasting evidence of Hotspot, audio-visual replays and eventually Snicko.

He said: "I don't know whether it's because it's the Ashes that the cricketing gods have thrown up so much inconclusive evidence, but we're a little bit confused at the moment as to why certain decisions have been overturned and certain decisions haven't been overturned."

He hopes nonetheless international cricket's administrators can eradicate problems which are currently evident.

"Both sides have been quite (confused) by some of the decisions that have occurred," said Cook.

"I think it's pretty even, but I hope the ICC can iron things out."

England have added pace bowlers Chris Tremlett and Graham Onions in a squad of 13 for Chester-le-Street to the XI who played in Manchester.