At a meeting before the European Community summit in Madrid in June 1989, Lawson and Foreign Secretary Geoffrey Howe forced Thatcher to agree to the circumstances under which she would join the Exchange Rate Mechanism.
Nun encontro antes do cume da Comunidade Europea en Madrid en xuño de 1989, Lawson e o Ministro de Exteriores Geoffrey Howe forzaron a Thatcher a acordar as circunstancias baixo as cales ela unir ao mecanismo de intercambio de proporcións, unha preparación para a unión monetaria.