Lewis Ludlam is one of three Saints stars named in England's World Cup training squad.
Courtney Lawes and Piers Francis are also part of the 38-man group that will assemble at The Lensbury Hotel on Sunday for the first official training camp.
It is a huge achievement for uncapped Ludlam, who has been working with the England squad in recent weeks.
The 23-year-old enjoyed a stellar season with Saints in 2018/19, becoming a fixture in the back row for the black, green and gold.
And he will now hope to make even more of an impression on England boss Eddie Jones as he shapes his squad for the World Cup, which starts for the Red Rose against Tonga on September 22.
Francis is included after establishing himself at inside centre last season, while Lawes remains a consistent member of the England camp.
"We can’t wait to have the full squad in place and to have players competing for those 31 places," said England boss Jones.
"It is a process of building the team up, building the cohesion, the tactical understanding of the team and our adaptability.
"We will need to get those things right to win the World Cup, and that is our aim.”
The Red Rose England will play Wales (August 11) and Ireland (August 24) at Twickenham Stadium and Italy (September 6) in Newcastle as part of the Quilter Internationals as well as an away fixture against Wales (August 17) in Cardiff.
England will travel to Treviso, Italy for a heat camp from July 22 until August 2 before returning to Italy on August 28 until September 5.
The squad will also be based in Bristol for a week in July (14-18) and in August (12-16) ahead of England’s away match against Wales.
For the two matches against Wales and Ireland at Twickenham Stadium, the squad will train at Pennyhill Park.
England will begin their Rugby World Cup campaign against Tonga in Sapporo before playing USA Rugby in Kobe (September 26), Argentina in Tokyo (October 5) and France in Yokohama (October 12).
And Jones added: “World Cup selection is a four-year process.
"We have looked at the squad carefully, tried to build up a squad that has enough experience, attitude and energy to be winners and I think we have that.
"In the process, we have left out some players who can feel unlucky.
"For those guys who have missed out, the door is never closed but they have just got to be ready, as you never know when the opportunity comes.”
Following two weeks of England training camps, Jones said: “The last two camps have been a head start for us.
"It has allowed the guys who didn’t play in the semi-finals or final to get some good conditioning work in and also some fundamental skill work so we expect them to set a high standard when the rest of the squad join us on July 7.
"The players have come in the best physical condition I have ever seen an England squad.
"The attitude of the players is that they are excited and hungry, they want to do well for themselves, their family and for their country."
“For the fans it is the start of the journey so we want you to be with us; we are all in this together.
"We are looking forward to seeing your support.”
England World Cup training squad
Dan Cole (Leicester Tigers, 85 caps)
Luke Cowan-Dickie (Exeter Chiefs, 11 caps)
Tom Curry (Sale Sharks, 10 caps)
Charlie Ewels (Bath Rugby, 10 caps)
Ellis Genge (Leicester Tigers, 9 caps)
Jamie George (Saracens, 37 caps)
Maro Itoje (Saracens, 27 caps)
Joe Launchbury (Wasps, 58 caps)
Courtney Lawes (Saints, 71 caps)
Lewis Ludlam (Saints, uncapped)
Joe Marler (Harlequins, 59 caps)
Ben Moon (Exeter Chiefs, 8 caps)
Brad Shields (Wasps, 8 caps)
Kyle Sinckler (Harlequins, 22 caps)
Jack Singleton (Saracens, uncapped)
Sam Underhill (Bath Rugby 9 caps)
Billy Vunipola (Saracens, 41 caps)
Harry Williams (Exeter Chiefs, 17 caps)
Mark Wilson (Sale Sharks, 13 caps)
Danny Cipriani (Gloucester Rugby, 16 caps)
Joe Cokanasiga (Bath Rugby, 4 caps)
Elliot Daly (Saracens, 30 caps)
Owen Farrell (Saracens, 70 caps)
George Ford (Leicester Tigers, 55 caps)
Piers Francis (Saints, 4 caps)
Willi Heinz (Gloucester Rugby, uncapped)
Jonathan Joseph (Bath Rugby, 40 caps)
Jonny May (Leicester Tigers, 45 caps)
Ruaridh McConnochie (Bath Rugby, uncapped)
Henry Slade (Exeter Chiefs, 22 caps)
Ben Spencer (Saracens, 3 caps)
Ben Te’o (unattached, 18 caps)
Manu Tuilagi (Leicester Tigers, 32 caps)
Anthony Watson (Bath Rugby, 33 caps)
Ben Youngs (Leicester Tigers, 85 caps)