Offspinner Saeed Ajmal and fast bowler Umar Gul led Pakistan’s convincing charge toward a clean sweep against England, reducing the top-ranked team to 6-173 at tea on the fourth day of the third and final Test.

England still needed a further 151 runs to avoid their first ever whitewash against Pakistan, with Matt Prior batting on 10 and Stuart Broad not out on 4.

Ajmal (3-44) struck in his successive overs after lunch, ending Alastair Cook’s four-hour knock of 49 before baffling Kevin Pietersen (18) with a delivery that went between bat and pad.

Gul (2-31) also rattled England in the space of four deliveries by removing Ian Bell (10) and Eoin Morgan (31) to bring Pakistan closer to a historic win.

Leftarm spinner Abdur Rehman kept the pressure on England’s batsmen throughout the two sessions by bowling 30 overs unchanged from one end.

Pietersen lofted the leftarmer over the head for a four and a six in one over, but it was the only brief highlight in an otherwise struggling four hours for Englishmen on a wearing wicket.

Earlier, Pakistan fielders had a scratchy morning after England resumed at the overnight score of 0-36.

Cook, who was dropped on four on Sunday evening, had another life on 28 when Gul misjudged a top-edged sweep in the deep that went for a boundary.

Pakistan wasted their last DRS referral when Ajmal thought he had Cook lbw on 37, but the television replays clearly showed that the ball pitched outside the line of leg-stump, much to the disappointment of Pakistan captain Misbah-ul-Haq.

Strauss and Cook resumed England’s pursuit of a tough 324-run target with some confidence before Gul found the outside edge of the England skipper’s bat, but wicketkeeper Kamran Akmal dropped a regulation catch.

Strauss was out soon after when he was trapped lbw by Rehman off a delivery that spun back sharply from the rough.

Even the DRS referral couldn’t help Strauss and he began the long walk after replays showed the ball would have hit the top of middle stump.

Trott then swept high to Rehman in the deep off Ajmal, who now has 23 wickets in the series.

England have just once successfully chased down more than 324 before to win a Test match when they made 332 in 1929 to beat Australia by three wickets at Melbourne.