Prezzo, Marston's and Patisserie Valerie have been announced as new members of the Association of Licensed Multiple Retailers (ALMR).
The news comes ahead of the organisation's 25th anniversary spring conference, set to be held in London tomorrow (4 May 2017).
The hospitality businesses are among a raft of new membership recruits that includes restaurant companies PizzaExpress, Leon, Wagamama, Busaba Eathai, Itsu and Wahaca, along with pub firms New World Trading Company and Urban Pubs & Bars.
ALMR chief executive Kate Nicholls said: "The recent influx of members has helped to boost our ranks and solidify our position as the leading voice for the eating and drinking out market in the UK."
She added: "It's clear that the industry is increasingly recognising the value and crucial importance of campaigning and speaking to government with one voice.
"In the run up to the general election, we will continue to champion our sector to key stakeholders across all political parties as a crucial growth champion with turnover of £60b, employing over 1.5 million people."
The ALMR represents more than 90% of all casual dining brands, managed pubs, nightclubs and bar operators. Its 220 operating company members account for more than 26,000 outlets and 650,000 employees.