In his letter P J House (18 February) describes the Lisbon Treaty as “self-amending” and states “Self-amending means they can move the goalposts any way they want, without our approval”.

However, once we look at the Treaty, the idea that “they” – whoever “they” are – can do this quickly collapses.

The Treaty introduced the “simplified rev-ision procedure” as a procedure by which parts (not all) of the Treaty could be amend-ed. This requires unanimity in the European Council (so it can be blocked by the PM) after consultation with the European Parliament, European Commission and (if relevant) the European Central Bank, and cannot enter into force until “it is approved by the Member States in accordance with their constitutions”.

Sections 3 and 4 of the European Union Act 2011 make clear what the UK’s constitutional requirements are an Act of Parliament and (in some circumstances) a referendum.

Rather than there being a “they” who can move the goalposts without our approval amendments to the Lisbon Treaty under the “simplified revision procedure” require the approval of the PM and of Parliament.

Graham Pointer (Dr), Shirley, Southampton