TORY leader David Cameron came under fire from the Labour party yesterday after he warned that Britain could struggle to repay its debt.<br /><br />Speaking at the Royal Society of Arts, Cameron said that increased government debt runs the risk of higher interest rates and &ldquo;not being able to meet your obligations&rdquo;.<br /><br />However, the opposition leader added that he was not actually predicting that the country would default on its debt, which is set to double to &pound;1.4 trillion in the next five years.<br /><br />&ldquo;But as government borrowing goes up and up and up, you start running that risk,&rdquo; he said.<br /><br />Labour hit back at the comments, branding them &ldquo;political naivety&rdquo; and &ldquo;economic policy by innuendo&rdquo;.<br /><br />&ldquo;It was an extraordinarily stupid thing to say which betrays his inexperience and opportunism,&rdquo; said an aide to Alistair Darling.