Staff at bakery chain Greggs are set to pocket around £300 each after the company announced a £7 million windfall payment to employees following a "phenomenal year".

The company said its underlying pre-tax profit, even with the payout to staff, would be ahead of expectations when it announces the 2019 results in March.

Greggs' 19,000 employees who have been with the firm since before 31 March 2019 will get £300 each, while the remaining 6,000 staff members will be paid £75 per quarter they have worked for the baker.

The bonus will be made at the end of this month.

"I am delighted to announce that we will also be making a special additional payment to all of our colleagues across the business who have worked so hard to deliver this success in what has been a phenomenal year," chief executive Roger Whiteside said.

It comes a year after the launch of Greggs' much-hyped vegan sausage roll, which has helped push up sales and extend the chain's appeal to a new audience.

The meat-free pastry snack has been followed by other initiatives with the recent launch of a vegan steak bake, and a vegan doughnut.

It promised to keep evolving to cater to other chosen diets.

Greggs opened 138 new shops, while closing 41, over the year, bringing its total to 2,050 across the UK. It said it plans to add a further 100 throughout 2020.

Sales grew 13.5 per cent, compared to 7.2 per cent growth in 2018.

Like-for-like sales, which strips out the effect of shop openings and closures, were up 9.2 per cent.

"Looking to the year ahead, we face strong sales comparatives and cost inflation headwinds present a challenge," Mr Whiteside said.

Among these challenges, which were predicted to be tougher than in recent years, are the increase in national living wage costs, the business said. It also warned that the rising price of pork was likely to impact the business.

In October, Greggs said it was stockpiling key ingredients, such as pork, ahead of Brexit.