Michael Portillo, the former cabinet minister and chief secretary to the Treasury, says the UK was right not to join the euro, citing 13 years of growth as the bedrock of the economy.Writing exclusively in Mortgage Strategy ahead of his address at the Mortgage Summit this week, Portillo says it’s interesting that in a steady state, this country’s interest rates are more than double Europe’s. But he adds: “Some will see that as an argument for joining the euro. I see it the other way round. We may have uncertain economic prospects today but while controlling our own monetary policy we have enjoyed 13 years of continuous growth.” He points out the contrast with Germany which has struggled under the European Central Bank. Portillo will speak at the gala dinner at this week’s Mortgage Summit in Jerez, Spain.