Alec Stewart is warning that the hardest part of Surrey’s bid for the Specsavers County Championship title is yet to come.

They restart their programme at Trent Bridge on Sunday against nearest rivals Nottinghamshire, who are 22 points behind, having played one more game.

After four straight wins, Surrey are being tipped for their first Championship success since 2002. But Stewart knows the remainder of the four-day campaign is anything but straightforward.

“The second half of the season is always the toughest part,” said director of cricket Stewart. “Inevitably, when you are top everyone wants to beat you. And sides have their own targets, like fighting for survival.”

So far, Surrey have done the double over both Hampshire and Yorkshire, but have yet to play either Notts or defending champions Essex. The past two weeks have been dominated by the Vitality Blast, where Surrey followed defeats against Middlesex and Kent with victories over Essex and Sussex.

Their efforts to get back into first-class mode, aided by a three-day game against West Indies A at the Oval this week, are complicated by having to visit Canterbury for another T20 clash with Kent on Friday night before heading to the midlands. It is the only Championship game until mid-August, when an intensive run-in to the end of the season will stretch the durability of every squad.

“Switching from one format to the other isn’t ideal, but it’s what we have to confront and underlines how adaptable players have to be,” explained Stewart.

“The players who haven’t been involved this week have spent a couple of days on red ball skills and then a couple more on the white ball game.”

Having crushed Yorkshire at The Oval, Hampshire at the Ageas Bowl and then Somerset at the Guildford Festival ­– all by an innings – Surrey had a harder battle in the return with Yorkshire, fighting back from a 75-run deficit in the first innings to win by seven wickets.

Stewart reckoned: “It was our best win of the season. We dominated the other matches pretty much from the start, but at Scarborough we had conditions against us and still turned the game around. That’s the mark of a good team, but we’re aware there is an awful lot of cricket to come.”

Hard-hitting Australian Aaron Finch is available for the Nottinghamshire clash, but Jason Roy’s finger injury may keep him sidelined.

Finch had been badly missed in Surrey’s opening Vitality Blast games and he returned in blazing form. His 58, together with contributions from Ben Foakes (56) and Ollie Pope (31), plus Rikki Clarke’s hurricane 48 not out in 20 balls, lifted Surrey to a formidable 222-4 against Essex at The Oval. The visitors could only manage 183-7 in reply, Varun Chopra making 67 as Mat Pillans and Gareth Batty claimed three wickets each.

Finch was utterly dominant 24 hours later at Hove, his unbeaten 131 in 79 balls featuring 10 fours and seven sixes. Surrey’s 192-3 never looked likely to be caught and only Phil Salt (74) held them up before the hosts were dispatched for 140.