Former Tory Cabinet minister Ken Clarke has questioned the strength of the recovery, claiming the economy is still "fragile".
Mr Clarke, who retired from the government in the reshuffle, said the economy is "not firmly enough rooted" in a balance between manufacturing and services, leaving it prone to shocks.
The former minister did however declare himself a "great fan" of Chancellor George Osborne and said the Conservatives had saved the country from calamity by reining in spending.
Clarke, 74, told the Observer that the economy still has a "long, long way" to go before sustainable levels of growth could be maintained.
The former chancellor added that Britain must break out of the "ludicrous cycle" of house price booms followed by crashes.
More top news
Teachers and managers in particularly are putting in hundreds of hours of overtime free of charge.
Labour have lost the Copeland by-election, a seat they had held since 1983, as the Conservatives edged the vote by 2,000 votes.
Labour have held onto the crucial seat of Stoke-on-Trent, brushing aside UKIP leader Paul Nuttall in the process.