VALLADOLID, Spain (Reuters) – After missing out on the points classification title in this year's Tour de France despite winning five stages, Britain's Mark Cavendish is optimistic about landing the Tour of Spain equivalent.

With five days remaining the HTC-Columbia sprinter holds an 18-point advantage in the category over Spain's Joaquim Rodriguez, the overall race leader.

"The points classification wasn't an objective at all when I came here and it came as a surprise when I first got it without winning a stage," the 25-year-old Cavendish told Reuters on Tuesday's rest day in Valladolid.

"But the green jersey's definitely a goal for me now. There are two definite sprint stages left, at Salamanca and Madrid, and another one that maybe I could do something in at Toledo."

"I think in any case Rodriguez is more interested in the overall race so I'm feeling pretty confident," added Cavendish.

The Briton has notched 22 stage wins on the Tours of France, Spain and Italy, including two in this year's Vuelta, and is keen to secure his first victory in the points competition of a top-three stage race.

"I've never won that points jersey before and it would be good to do it," said Cavendish.

"But that's not our only objective for the team, we've got a rider Peter Velits of Slovakia in the top 10 overall, we won the team time trial and we've had guys in breaks.

"There's only two guys in our team left here who are over 25 so it's a young squad but we're doing really well."

Cavendish said he would like to gift a stage to key wingman Matt Goss of Australia before the end of the race to thank him for his work.

"I tried to let Matt take a stage before I made the green an objective and it didn't quite work out. But if I've got the points jersey secured then I'd really like to do that," added the Isle of Man rider.

Rodriguez said he was closing in on the biggest victory of his career.

"I'm in the best position possible, even if the time differences are small," the Katusha rider told reporters, referring to his 33-second lead over Italian Vincenzo Nibali.

"If I can hold on to the jersey in tomorrow's time trial, then great, but it's Saturday's last stage in the mountains where I'll be on the attack. That stage could change my life."