World Cup winner Phil Vickery believes Saracens' Mako Vunipola is losing his battle with Joe Marler to be England’s starting loosehead against Fiji at Twickenham on September 18.

While Marler endured a miserable campaign at club level last season, as a combination of injuries and poor form at Harlequins hindered him, Vunipola enjoyed a hugely successful season in a Saracens shirt as the club went on to lift the Premiership title.

Marler started against Ireland at the weekend as Stuart Lancaster’s men warmed up for the World Cup in perfect fashion by winning 21-13 at Twickenham – but once again it was far from a convincing performance up front for England.

Vunipola replaced Marler after 55 minutes – but in the short-term it seems as though Lancaster will persevere with his premier front row of the Harlequin, Tom Youngs and Dan Cole.

Although England's cutting edge out wide was razor sharp, the current pack lost two scrums against the head – something unheard of in recent years – and is still to convince it can lay the foundations for global domination.

“I think the loose head battle is pretty fierce for England presently but I think Joe Marler has just about done enough to make the shirt his own ahead of Mako Vunipola for the World Cup,” said Vickery, who is encouraging people to show their support of children’s rugby franchise, Rugbytots, as they take to the roads to tackle their impressive World Cup Bike Ride, raising vital funds for Wooden Spoon – the children’s charity of rugby.

“He has had his injuries last season and did not have a particularly good year at Harlequins having been given the captaincy and I think that was an issue for him.

“I think Mako Vunipola offers a different kind of option for England, with potentially more impact off the bench, although I don’t like to just say he is an impact player – he’s better that that and will keep Joe Marler on his toes throughout the tournament.

“I think Mako Vunipola can be a lot more than a replacement for England but we have two varying props in the squad, which I think is always good from a selection point of view.

“It’s up to those two now to really fight it out and get the best out of each other ultimately for the England team – the performances so far in the warm up games mean positions in the front row are certainly up for grabs.

“You have to have those internal battles going on all over the park, not just the front row, the second row, back row and half backs – you have got to keep those little mini battles going.”

If you’d like to sponsor the riders, who over four gruelling days of cycling, took in iconic stadiums in England and Wales who’ll play host to Rugby World Cup matches visit www.justgiving.com/teams/rugbytots For more information about who Wooden Spoon support, visit www.woodenspoon.org.uk