Media playback is unsupported on your device Media caption What will happen to Polish shops?

As EU migrants face a backlash in Cambridgeshire in the wake of the referendum result, the entrepreneur behind a small chain of Polish delis fears for her future.

Elena Hrabovenska goes to the staff area to retrieve the letter from her handbag. From the way she has spoken about it, I'm expecting a long, heartfelt message. But it's a simple note scrawled on scrap paper:

"My wife told me that hate mail and phone calls have been made to the Polish shops in Huntingdon. The people who do this are a minority. The Poles add to Britain: they have always been welcome."

Days after the historic referendum to leave the EU, cards with the words "No more Polish Vermin" were left outside schools and homes in Huntingdon, where Elena runs a Polish deli.

"On that day five British people came into the shop and they said they are really sorry. They are ashamed of that person who's done it."

Elena's main concern, she says, is that words will escalate to physical violence.

Image caption Elena keeps the message of support given to her shop after hate mail was sent to Poles in Huntingdon

After struggling to find the right words, she says: "Around the world you will always find someone who has the stone instead of the heart."

Deli dreams

Elena owns three Polish delis, one in Huntingdon and two nearby in Peterborough.

She came to England in 2003 from Ukraine, aged 19. She arrived alone on a working visa, with £100 in her pocket. She knew nobody.

At the time there was only one shop selling Central and Eastern European food in Peterborough, she recalls.

Despite having a good grasp of English, she struggled to find the ingredients she needed to make the traditional soups she missed. This gave her the idea to open a deli with food imported from Central and Eastern Europe, with staff that can speak Polish and Russian.

A few years after arriving in the country, her first deli was born.

Image copyright Elena Hrabovenska Image caption Elena's original Nectar shop in Lincoln Road, Peterborough, is popular with migrants

To stock that first shop, her husband would continually make the 36-hour round trip to Poland by van.

There was a clear business opportunity as more and more Poles arrived in the UK, after they were given the right to work here in 2004.

Elena's business grew and a decade later, she employs 20 people and has two refrigerated trucks making the journey to Poland and back.

There is an obvious irony, of course, that she was a Ukrainian building a Polish deli empire. But in fact many of the Polish delis that have emerged in the UK are owned by non-Poles. Many are run by Turkish businessmen and women. It is a similar phenomenon to Bangladeshis owning Indian restaurants.

'I feel responsible...'

When asked how she feels about the referendum result, her first thought is for her business.

"We put against this business basically everything, the time we could spend as a family... to achieve this place we would work 48 hours without a wink [of sleep]."

Her fear is that her delis will be hit by a weaker pound and ultimately, if the UK leaves the single market, import tariffs on Polish food.

Image caption Traditional sausages appeal to homesick Central and Eastern Europeans

"I feel responsible for my staff. I don't want to face that time when I have to announce, 'I'm sorry girls I have to close, I have to cut staff or hours.' They have families as well, they have children.

"All of them were asking what is going to happen and I didn't want to answer.

"[But] I know we live in the 21st Century, someone is not going to knock on our doors and throw us away."

Referendum aftershocks

Peterborough voted by 60.9% in favour of leaving the European Union.

Customers have not talked about it, "like they are in shock", says Elena.

Image copyright Elena Hrabovenska Image caption Elena's second shop in Huntingdon, where her staff received messages of support

But the result did not surprise her. She has noticed ill-will towards migrants in the city.

Peterborough is often cited as a place strongly affected by EU internal migration.

The last census revealed that its population rose by almost 18% between 2001 and 2011, reaching 183,631. People from Central or Eastern Europe made up 7.7% of the city's population by 2011. Many are drawn by the seasonal farm work available nearby.

"Some immigrants are not perfect and put a black mark on the immigrant's name," says Elena.

However, she says she wants people to remember that "a lot of families are coming here to seek a better life and work hard".

Posh Polish

Her latest, newly-opened shop is a bright mini-supermarket, neatly tucked behind a Tesco, nestled next to a Chinese takeaway.

Image caption Elena in front of her newly-opened third shop, in Peterborough

She reckons 25% of her customers here are English.

With so many rival Polish delis, she explains, she has had to open this larger shop to compete on choice.

Despite successful expansion, migration of another kind has posed the biggest threat to her business, she explains.

Gridlock at Calais caused by illegal migrants has disrupted her fragile supply chain. She has had to unload trucks through the night to make up for lost transit time.

Symbols of failure?

On one of the walls in Elena's shop you will see Polish football scarves, magazines, adverts and books that are all in Polish.

Image caption Polish books and translations are on display in the shop

"When customers come into the shop they think they are back in Poland," remarks Elena.

So does she think shops like hers represent a failure to integrate with the local community?

This kind of shop "will vanish", she predicts, after a pause, by way of answer.

"There is a new generation coming. Obviously they will still have in their hearts that their parents were Polish, but they will integrate into the English community as happened with other nationalities.

"There will be mixed families, with Polish mums and English dads, for example, two cultures mixed together.

"It's going to soften."

Follow business reporter Dougal Shaw on Twitter.

This feature is a part of a new series from the BBC Business Unit called My Shop. To suggest a shop email us.