James Brown, Sainsbury's clothing director, said the investment was part of Sainsbury's wider corporate strategy to grow its non-food business and further diversify its revenue and profit streams.

He added: "After an outstanding performance over the past couple of years it's the right time for a significant investment in the brand."

"I think it's so important," she said. "They are phenomenal, these businesses, they truly are the backbone of the economy and the shining lights of this country and we've tried to do our bit but we really need to make sure everybody is making sure that they are truly showcased in the way that they should be.

"A lot of it is about financial support. I am personally very conscious that 95% of our businesses are women. For us, when we launched and indeed for many of them, the greatest issue is simply childcare. Amazing entrepreneurs with amazing ideas being hampered by such a basic practicality seems crazy."

Mrs Cornish said launching the web business was "not easy" but added: "You do the best you can, there is no real work-life balance, of course there isn't, but I think it's about making sure you're comfortable with the way you're doing it, knowing that you are doing it for the right reasons, for your family and your business, and then get on with it."

The entrepreneur, who lives in Teddington, west London, with her husband Simon, 47, and children Ollie, 16, and Honor, 14, described her accolade as a "testament" to the company's small business partners.

She added: "It was a highly emotional moment when I received my letter, not least because when I ran upstairs to show my husband, his eyes welled up with tears. It really is a dream come true and we are so particularly touched to be recognised in this way.

"We have always felt so privileged to have the best job in the world, growing our company and championing small businesses across Britain and abroad. Seven years ago, when we launched notonthehighstreet.com, we hardly dared imagine that we would now be supporting over 3,500 small businesses."

With beefburgers, the Birds Eye Original version cost £8.30 per kg and contains 77% meat but Tesco's quarter-pound beefburgers cost £6.12 per kg and contain 90% meat, Which? said.

According to food labelling guidelines, a pork sausage must contain at least 42% pork meat to be labelled as such and that a product described simply as sausage only needs to contain 32% pork, 26% chicken or 30% beef/lamb.

Sausages and bacon are the most popular meat products sold by retailers, with 74% of UK adults buying them, Which? said.

Four-fifths of people (79%) check ingredients and meat content on labelling, the consumer group said, but added that it is concerned that government proposals will weaken guidelines and decriminalise violations of food labelling rules.

"We want mislabelling to remain a criminal offence, even more so after the horsemeat scandal, so those responsible for misleading consumers can be held to account," Which? said.

Executive director Richard Lloyd said: "It's important that people know what they're getting so they can make an informed choice. In the wake of the horsemeat scandal, we want the Government to think again over their plans to decriminalise food labelling offences to help restore trust in the food industry."