Greggs is working on vegan versions of all its bestselling products, from steak bakes to pasties and doughnuts, as the high-street baker looks to repeat the runaway success of its vegan sausage roll.

The Quorn-filled roll, which launched in January, was so successful that Greggs had to increase production to satisfy demand. The sales boom also increased profits, with the business going back to City investors several times last year to say it was making more money than it had expected.

Greggs’ chief executive, Roger Whiteside, upped the ante on Friday when he revealed its developers were working on vegan recipes for all of its most popular products.

“We are working away to see if we can come up with a version of all our bestselling lines because people want vegan options,” Whiteside told LBC. “If we can produce something that tastes just as good as the meat version, then that will sell very successfully. That’s what’s been shown with the vegan sausage roll.”

Last month Whiteside told reporters the company was working on a vegan doughnut and plant-based milks but he refused to drawn on what the next big launch would be, saying: “That would be giving away everything to our competitors.”

Greggs, which sells 1.5m traditional pork sausage rolls a week, is benefiting from the growing number of Britons who choose to eat less meat or have switched to a plant-based diet. In recent years there has been a huge uptake of veganism in the UK with the number increasing from 150,000 in 2014 to 600,000 in 2018, according to the Vegan Society.

This shift in attitude has led to manufacturers, supermarkets and restaurants scrambling to cash in. The consumer goods firm Unilever has bought the meat-substitute company the Vegetarian Butcher and the UK’s first 100% vegan hotel has opened in the Scottish Highlands.

The filling in the vegan roll is a fungus-based protein that is mass-produced by the meat-free specialist Quorn Foods in its factory near Darlington, County Durham. Sales were given an early boost by Piers Morgan, who turned it into a national talking point by tweeting that Greggs bosses were “PC-ravaged clowns” for putting it on the menu. Greggs’ own Twitter account responded with: “Oh hello Piers, we’ve been expecting you.”

Greggs, which was founded by John Gregg as a Tyneside bakery in 1939, has been completely reinvented by Whiteside, who took charge five years ago. The former Ocado and Marks & Spencer executive saw the writing was on the wall for its traditional bakery model as changing shopping habits meant Britons were increasingly buying their bread at the supermarket.

Whiteside overhauled the menu, adding healthier options such as soups and wraps as well as speciality coffees and breakfast options including porridge and granola, enabling it to move into the booming food-to-go market, which is worth more than £18bn a year.

The new approach helped the no-frills retailer win over “Greggs rejectors”, as Whiteside calls them, and turned it into a serious rival for chains such as Pret a Manger. Its latest plan is to enter the takeaway dinner market, keeping its shops open until 9pm.

Whiteside says the vegan sausage roll has helped change the perception of Greggs from “an old-fashioned bakery from the north” to a “modern food-on-the-go brand”. “The thing that people misinterpret in the UK market is that if it’s low price it must be low quality,” he said in a recent interview. “But customers are wising up to that because of what I call the Aldi/ Lidl effect. Low price doesn’t have to be low quality.”

The reinvention of Greggs has been good news for shareholders, who were handed a £35m special dividend in July after sales at established stores leapt 10.5% and profits jumped more than 50% to £40.6m in the first six months of 2019. Its shares have almost doubled in value over the past year and are now changing hands for around £20.