Access to that common market has, to this point, required a commitment to the Four Freedoms, free movement of goods, services, people, and capital.
Are you suggesting the UK will be able to negotiate access to the common market without acceding to those four freedoms - something which has never happened before and considering the current EU stance of "hurry up and gtfo" seems quite unlikely.
Or are you suggesting the UK will leave Europe, but still allow free movement of people in order to retain access to the common market? Immigration control was given as the second most important factor by those who voted leave, that would be quite some turn-around.
Or, finally, I guess you could be suggesting that Britain will be a good place to do business in Europe without being a part of the common market.