You will find some very useful information on the business link website:
There are many cash & carry businesses in the UK who source fruit and veg from various parts of EU and around the world. You will need to list the items you would like to sell in the UK, and do a cost comparison between the price they are selling it and the price you are willing to sell including your costs. There are many other things you will have to look for like the demand, transportation costs etc.
I would suggest you search for Cash & Carry businesses in the UK and contact them with your offering, never know you might get lucky.
We can also help you with a quick market research in terms of contacting companies and passing on their responses to you, for a charge. If you are interested, please send me a PM and we can take it from there.
it is good to ask the right office in the UK if they don't need any certificates, e.g. concerning the quality control? if you ask about business in Poland - you should just have all the documents as each company (tax matters, social security..)