Nick Clegg mocked Alistair Darling as a ventriloquist's dummy delivering his master's words, as he attacked what he called "a tinkering, con-trick Budget that protects the rich and abandons the poor".
In his first Budget response as Liberal Democrat leader, Mr Clegg derided claims over the Budget's green credentials, insisting it was a "green cop-out".
He said: "It is a Budget designed to fill a black hole, masquerading as good for the environment. It is a Budget that will not make Britain fairer."
Mr Clegg said environmental levies would raise £1.7bn in revenue, but only £1bn of that would be diverted to help people on lower incomes, arguing that the cash would instead fill a "black hole" in the Chancellor's finances.
He declared: "Green taxes should be revenue-neutral. They should not be treated as a wheeze to squeeze ever more money out of the British people, but should instead be designed to encourage green behaviour and cut the taxes of the most needy."
Mr Clegg added: "This is not a budget for the environment, it is a budget driven by fiscal incompetence and political desperation."
He accused Labour of completing a "fiscal fusion" with the Conservatives, arguing that both believe "in the same kind of budget; the kind of budget that kowtows to vested interests but fleeces the average family; the kind of budget that keeps tax loopholes for the super-rich but closes in mercilessly on single mothers who have been overpaid tax credits; and the kind of budget that uses green taxes as an excuse to take more money from the kitty of low earners."
He accused the Government of lacking the "guts to claw back the huge excess profits made by energy companies thanks to the emissions permits that the Government has given them for free".
Mr Clegg attacked Mr Darling, but also turned his fire on the Prime Minister, insisting he was the organ grinder to the Chancellor's monkey. He said: "The Chancellor is the Prime Minister's creature, struggling to clear up a mess left by his boss under instruction from No 10.
"What we have seen today is an act of political ventriloquism. I would like to compliment the Prime Minister; I watched him very closely and his lips barely moved all the while that the Chancellor was speaking."
Mr Clegg said it was "disingenuous" to lay the Government's economic woes at the door of the American sub-prime mortgage market. Instead, he said the economy was faltering because of "a swelling tide of personal, private debt secured against high house prices that are now declining", saying the situation was "creating the conditions for a perfect economic storm".
He said: "High oil and food prices make it difficult for the Bank of England to cut interest rates and with Britain now up to £2trn in debt the Chancellor has backed himself into a corner with no room for manoeuvre.
"Deep in the red, the Government keep betting more and more of our money in the hope that someday, somehow, they will find themselves back in the black. As we have heard today, that prospect is moving ever further into the distance."
Mr Clegg attacked the Budget for doing nothing to assist lower-income families. He said: "This Budget gives no real help to families struggling with higher food bills, higher energy bills and higher debt repayments. What will this Budget do to help junior nurses, teaching assistants and soldiers serving in Afghanistan? The answer is nothing."Reuse content