1. The EU cannot override the UK in these areas:

2. UK government ministers win the vast majority of EU votes
Since 1999, UK government ministers have been on the losing side 56 times in the EU Council of Ministers, and on the winning side 2,466 times.

The EU Council of Ministers reviews all EU legislative proposals. No new EU laws can be agreed without its approval.
3. The UK has secured more EU opt-outs than any other member state:

4. The UK has the least regulated economy in the EU
The UK has managed to maintain the least regulated economy in Europe over 40 years of EU membership.
5. EU single market access comes at a cost

Source: Politics.co.uk, 15/01/14
Norway and Switzerland refer to this as ‘fax democracy’ because it means in return for free trade with the EU they have no influence over EU regulations.
Norway pays roughly the same amount per person for access to the European Economic Area (EEA) as the UK pays to be a full EU member.
5. Germany says no exceptions for the UK
Germany has indicated it will not accept any deal for full UK access to the single market after a #brexit, unless the UK is willing to accept free movement of people and the supremacy of EU single market law.

Source: The Guardian, 10/06/16
EU rules mean any deal for access to the single market after a #brexit would require unanimous agreement from the remaining 27 EU member states.