Letter published in the Guardian, 28 May 2014:

On the issue of fiscal convergence, David Cameron must not repeat the mistake of Margaret Thatcher who ignored Nigel Lawson’s twice-repeated warning…. that “the inclusion of European monetary union as a treaty objective would be a political commitment going well beyond previous references to EMU.” Without a parity of esteem for an EU of multiple currencies there can be no basis for a UK renegotiation.

Read the full letter here