England opener Alastair Cook has warned his Test team- mates that New Zealand are shaping up to be tough opponents all over again.

Cook was made to graft for three hours at Chelmsford for a welcome half-century but could not prevent the under-strength Kiwis from beating Essex by 92 runs.

The visitors achieved their success even though captain and front-line spinner Daniel Vettori was unable to bowl in the second innings because of a finger injury which will also keep him out of this week's match against the England Lions at Southampton.

But Cook saw enough to predict more hard battles ahead for himself and his international colleagues.

"New Zealand are a highly competitive outfit and give nothing away," warned Cook, who helped England come from behind to beat the Kiwis 2-1 in a Test series on the other side of the world two months ago. "It's going to be another tough series.

"Hopefully, we can do the double over them but we can't just walk into the series expecting to do it because that's when trouble happens."

Not that Cook anticipates any complacency from England once battle begins at Lord's on Thursday week.

"South Africa [this summer's second visitors] may be the bigger draw but New Zealand beat us in the one-day series over there and it was close in the Tests," he said.

Essex were hopeful of chasing down a victory target of 293, especially with left-armer Vettori out of the attack after cutting his spinning finger earlier in the contest.

"We fancied our chances," Cook said. "The pitch perhaps died a bit but all credit to the way they bowled."

Mike Mason (right), who eventually had Cook caught at mid-off for 57, was the pick of the Kiwi pace pack.

He finished with three for 36, dismissing both Mark Pettini and James Foster for ducks, and could yet force his way into the First Test.

Teenager Tim Southee, who made an impressive debut against England in Napier at the end of March, is being treated for a back twinge. If he falls by the wayside, then either Mason or Iain O'Brien will start this series.

"Their bowlers made us work hard over there and we saw how they can swing the ball both ways with good control," added Cook. "They stick to their guns very well."

Cook should have been out without scoring - he was dropped in the slips by Ross Taylor off O'Brien - but then made good use of his lucky escape.

"I'm very grateful to have spent a bit of time in the middle," said Cook, who dislocated a finger on the first day of the match but batted without any discomfort yesterday.

"I've got another championship game [against Middlesex this week] before the Test and, hopefully, I can keep the form curve going in the right direction."

But top form is proving elusive for most members of England's likely top order.

Michael Vaughan keeps getting out when apparently well set with the latest example coming against Durham in yesterday's Friends Provident Trophy clash at Headingley.

Vaughan moved into double figures for the fifth time in as many innings, only to fall for 22 when prodding paceman Graham Onions to point. Having batted seven times in all so far this season, England's captain has yet to reach 50 and is unlikely to bat again before the Lord's Test.

Durham's Paul Collingwood, meanwhile, completed a miserable holiday weekend by being dismissed for two in the same match, having departed for a first-ball duck against Lancashire 24 hours earlier.

Ian Bell managed only three for Warwickshire against Leicestershire, Andrew Strauss went for 26 as Middlesex lost to Sussex and Andrew Flintoff again failed with the bat after another fine bowling performance.

Flintoff took two for 18 from nine overs against Scotland but then scored only eight from 22 balls as the visitors to Old Trafford secured a shock two-run victory.

If England want to pick Flintoff as a specialist bowler for Lord's he looks ready and able following a fourth ankle operation, but with a top score of 27 not out this season he is struggling to justify all-rounder status.