He said Britain's future lay in being "outward looking and open-minded", not "closed-minded, anti-EU and anti-immigrant", suggesting such views were "reactionary and regressive".
"Attitudes that are closed-minded, anti-immigrant, anti-EU, 'stop the world I want to get off', those attitudes don't result in economic prosperity or power and influence in the world.
"There is a perfectly good, strong argument to be made - you have to go out and make it."
Mr Blair praised the Lib Dem leader Nick Clegg for his "leadership" in recent years but said the Lib Dems' poor performance in the polls was "nothing to do with Europe".
www.bbc.co.uk/news/uk-politics-27585260