Michael Portillo's column in the Sunday Times reflects on why the Conservatives have not opened up a significant lead in the opinion polls. Like most commentators, he suggests that Vince Cable's assured performance over Northern Rock for the LibDems has exposed the weakness of Cameron and Osborne, particularly in terms of being ready to lead an alternative government. Portillo suggests that neither those advocating caution or a more radical agenda for the Tories have a winning formula for the next election. He does think that giving Cameron another term in opposition would "guarantee him enough time as leader to complete the Tory revival and to achieve personal political maturity". Read the column http://www.timesonline.co.uk/tol/comment/columnists/michael_portillo/article3423672.ece