The private equity firm – which was set up in 2009 by Alan Dargan, Ross Finegan and David Gasparro – will use the funding to acquire a London cocktail bar chain.

Simmons Bars has 12 sites across London, including King's Cross, Camden, Clerkenwell, Soho, Liverpool Street, Fulham and Balham.

It was established in 2013 and has experienced a significant growth trajectory over the last three years (opening nine of its 12 bars).

Nick Campbell, co-founder and CEO at Simmons Bars, will continue to lead the business with the support of Lonsdale.

The cocktail bar chain will use this support to create additional sites across London as it aims to increase to over 30 bars in the short to medium term.

“Since our founding in 2009, our investment approach has been to back businesses operating in an attractive niche, with strong and ambitious management teams,” said James Knott, investment director at Lonsdale Capital Partners.

“Simmons is a perfect example of this: although it is a relatively young business, it has grown impressively over the past four years under the leadership of Nick Campbell and now boasts a well-located, profitable estate.

“In addition to this, it is positioned in one of the fastest-growing leisure segments in the UK.

“With this finance from OakNorth, we will be able to provide Simmons with the capital and expertise required to help it reach its full potential.”

Stuart Blair, debt finance director at OakNorth, added: “This is the first deal we've done with Lonsdale and emphasises our commitment to supporting private equity deals in the lower mid-market.

“Despite increasing competition, chains such as Simmons Bars have managed to carve themselves a niche and build a dedicated following in the cities in which they operate.

“With Lonsdale's support, Simmons will be able to pursue its ambitious growth plans of reaching 36 sites over the next four years.”