Reigning world champions David Smith and Greg Polychronidis headline the field for the 2019 Boccia European Regional Championships in Seville, where action begins today.
The winners from each of the four individual and three team medal events secure their nations a slot at the Tokyo 2020 Paralympic Games.
Greece's Polychronidis opens his campaign for a Paralympic title that has so far eluded him.
After winning his first major individual gold at last year's World Championships in Liverpool, Polychronidis enters the BC3 event as favourite.
He hopes to shake off results from the Hong Kong World Open in May, when he failed to reach the podium.
However, Great Britain's Patrick Wilson caused a surprise by leaving with the silver medal.
He and fellow Briton Jamie McCowan, the world number four, are also expected to be involved in the battle for BC3 honours.
Team mate Smith is likely to be a gold-medal challenger in the BC1 event.
But like Polychronidis, the world number one did not reach the podium in Hong Kong.
Daniel Perez, the 2018 world bronze medallist, is considered Smith's main challenger.
The Dutch star already holds a gold medal from the Montreal World Open in May, and finished third at the Olbia Regional Open in Italy in June.
Another top-seeded Briton is Stephen McGuire in the BC4.
The reigning European champion is looking to bounce back from a disappointing home World Championships in 2018, and he showed positive signs by winning in Hong Kong.
Germany's Boris Nicolai, the World Championship bronze medallist, is also targeting the same top prize.
He arrives on the back of a victory at the Olbia Regional Open.
The BC2 individual event is set to be wide open, as Slovakia's Robert Mezik aims to upgrade his silver medal from 2017.
European bronze medallist Abilio Valente of Portugal also has a similar target.
Action in Seville is due to conclude on Saturday (August 31).