John McDonnell says he'll be sick if George Osborne says 'fix the roof while the sun is shining' again

Shadow chancellor John McDonnell says he will "throw up" if George Osborne promises to "fix the roof while the sun shines" when outlining Conservative economic plans for the next five years.

In an interview with the New Statesman the day before the chancellor delivers his Spending Review and Autumn Statement, McDonnell told George Eaton that he had no patience for the Tories' 'long-term economic plan', dismissing Conservative fiscal rhetoric as unsophisticated "one-liners".

He said:

We’re going to have an intelligent and a mature economic debate.

If I hear again that they’re going to ‘fix the roof while the sun shines’ I will throw up. It’s nauseating, isn’t it? It reduces debate, intellectual debate, economic debate, to the lowest level of a slogan. That’s why we’re in the mess we are.

McDonnell made headlines in July for promising to "swim through vomit" to oppose the Tory welfare reform bill.

The bill was passed with 308 votes to 124, despite 48 out of 216 Labour MPs rebelling against the instructions of interim leader Harriet Harman.

McDonnell served as a backbench MP for 18 years before being catapulted to the shadow cabinet with the election of his friend and ally Jeremy Corbyn as party leader in September.

After his appointment McDonnell initially supported Chancellor George Osborne's plans to get the country running a budget surplus by 2020.

Osborne is likely to breach his own limits on welfare spending, reports ahead of the autumn budget statement suggest.

More: Here's how Jeremy Corbyn's shadow chancellor John McDonnell plans to reform capitalism