Lions boss Warren Gatland and his coaching staff put the finishing touches to their selection during a meeting on Tuesday afternoon and according to both the BBC and The Times, Hartley has been overlooked, with Rory Best, Ken Owens and Jamie George the preferred hookers.

Hartley has led Eddie Jones' side to two Six Nations titles, a Grand Slam, a series whitewash of Australia and a world record-equalling run of 18 Test consecutive wins but indications are he will be omitted, while uncertainty also surrounds centre Jonathan Joseph, fly-half George Ford and lock Joe Launchbury.

New Zealand-born Te'o, who has made one England start in eight appearances, shone in front of watching Lions assistant coach Rob Howley when Worcester beat Aviva Premiership opponents Bath three days ago.

And the 30-year-old might have done enough to surprisingly edge out razor-sharp Bath ace Joseph, although Wasps forward Launchbury being overlooked would be a bigger shock, given his outstanding England displays this season.

Gatland's second-row options are considerable, making selection in that department particularly demanding, yet Launchbury was still considered a shoo-in by many pundits.

Ford, meanwhile, looks to have lost out behind Wales number 10 Dan Biggar, with the the Ospreys fly-half featuring among a likely double-figure Welsh contingent in Gatland's expected 37 or 38-man party.

England's representation is set to be their largest since Clive Woodward selected 20 for the Lions' 2005 New Zealand expedition, but Scotland, despite winning three recent Six Nations games, could be left with full-back Stuart Hogg as their solitary squad member.

Wings Tommy Seymour and Sean Maitland, lock Jonny Gray and flanker Hamish Watson all have their admirers, while prop WP Nel would surely have made it but for injury, yet 2013 Lions tourist Hogg looks to be Scotland's only clear-cut choice, with Seymour pushing hard behind him.

European champions Saracens and Irish heavyweights Leinster could provide almost a third of the squad between them, with eight Aviva Premiership clubs likely to be represented on Gatland's roster as Saracens are joined by Bath, Northampton, Exeter, Wasps, Worcester, Leicester and Harlequins.

Lions tour manager John Spencer will announce the squad at midday on Wednesday.

Spencer will be joined by Gatland, his coaching staff and captain, who is expected to be Wales flanker Sam Warburton, at a hotel on the edge of the 200-acre Syon House Estate in west London.

Gatland then has 40 days to departure for New Zealand, with recent Lions history suggesting at least two injury or suspension-enforced changes likely before then.

The Lions kick off their 10-match trip against the New Zealand Provincial Barbarians in Whangarei on June 3, with the Blues, Crusaders, Highlanders, Maori All Blacks and Chiefs all on their agenda before the first Test three weeks later.