Alec Stewart column: The Ashes can wait - first focus on the Kiwis

England's two-Test match series against New Zealand is certainly not a warm-up for the Ashes.

While I understand the temptation for fans to be thinking ahead to the showdown with Australia, no-one inside the England camp will be looking any further than the first ball of the first Test at Lord's on Thursday.

They cannot afford to because if you take your eye off the ball for one moment in Test cricket you will very quickly come unstuck.

This is a vital contest in its own right because it gives England a chance to make up for the disappointing series draw in New Zealand and rediscover their 'A game'.

I felt England went into the series in New Zealand a little undercooked after playing plenty of one-day cricket but then just the one first-class match before the opening Test. They started poorly in Dunedin and had to rely on Matt Prior's match-saving heroics in Auckland on the final day to avoid a series defeat.

This time around, they have all been playing county cricket and have put in a meaningful performance or two for their counties.

They will be now be fully aware of the Black Caps' strengths and, just as importantly, their weaknesses which they'll be keen to expose through careful planning.

England certainly have a few points to prove and will want to put in a performance that fully justifies their position at number two in the Test rankings, six places above the Kiwis.

That is the plan but its execution will not be easy. As England found out in March, New Zealand are a rapidly improving side, expertly captained by Brendon McCullum. They have talented batsmen like Ross Taylor, Hamish Rutherford and Kane Williamson and seamers who could all prove a handful in English conditions.

The return from injury of batsman Martin Guptill and fast bowler Doug Bracewell strengthens their squad and they will be determined to back up their displays on home soil with a strong showing overseas.

In terms of selection, the England squad picked itself once Tim Bresnan and Graeme Swann had declared themselves fit.

Kevin Pietersen's injury gives Jonny Bairstow another chance to prove his credentials and potentially give the selectors a welcome headache for the Ashes.

When Pietersen is fit he will come straight back into the team, so each batsman will be keen to show their true worth by scoring meaningful runs. Should Bairstow post hundreds in both games while someone misses out, who is to say they will not stick with the Yorkshire batsman for the Ashes?

In the bowling department, I cannot see England going into the match without a spinner, so I see it as a straight fight between Bresnan and Steven Finn.

Finn is the man currently in possession and will be playing on his home ground. He will be familiar with the nuances of the famous Lord's slope, but Bresnan has been taking wickets for Yorkshire and has the ability to get the ball to swing.

The pitch, along with overhead conditions, will be the two biggest factors as to who gets the final nod.

These two matches just about constitute "a series" so whichever side hits the ground running at Lord's will be very firmly in the driving seat.

I'm backing England to win, so long as the weather stays fine, but at the same time know New Zealand will be looking to carry on where they left off at home and cause an upset.

Alec Stewart was talking to BBC Sport's Sam Sheringham.