In his latest letter, P J House (March 7) asks if I really believe my “theory” of how the Treaty of Lisbon is amended. It’s hardly a “theory” – if he looks at Article 48, then he can see that this is the process outlined in the Treaty itself.

Indeed, this process has already been used. In May 2011, the European Council unanimously agreed to amend Article 136 in order to introduce the European Stability Mechanism.

The UK Parliament passed the European Union (Approval of Treaty Amendment Decision) Act 2012 in order to ratify the proposed amendment. If Parliament had voted to reject the Bill, then it would not have been ratified, and therefore Article 136 would have remained as it was.

As this incident shows, the UK Parliament can – if it wants – block a proposed amendment to the Treaty of Lisbon.

The idea that the European Commission would have the final say, irrespective of anyone else, is completely baseless. As the Treaty of Lisbon is clear, the Commission’s powers when it comes to amending the Treaty are limited to the right to propose amendments to the European Council, and the right to be consulted.

Graham Pointer (Dr), Shirley.