Thanks for the quick answer...
I feel that I'm not totally getting your point. Please find below the original email I received from my CEO. As you can read, we received the advice from our lawyer and not a proper tax advisor.
So is this scenario below right or not?
The good news is that you would be eligible to purchase some of John’s shares, assuming the other share holders do not take up their premption rights. The bad news is that , like the options, the lawyers think there may be a tax burden and we need to get advice on that. For example, if you were to purchase the equivalent of 2%, that would equate to buying approx £16k of shares for £600. The HMRC may therefore claim you have “earned” £15,400 and would have to pay income tax on it. That could be as much as £6,000.