It could be that Brown has a cunning plan. Speculate about an October election. Get Cameron firing off all his salvoes in the form of his various policy initiatives. Then don't call an autumn election and pick and choose the best of Cameron's initiatives and implement them as government policy before the actual election next spring, or whenever.
No sooner said that done. Brown has nicked a policy idea straight out of the Conservatives' Quality of Life report, only a few days after it was published:
The Chancellor is planning to introduce a "purchase tax" of up to £2,000 on the most polluting vehicles, it has been claimed.
The idea is set out in a leaked Treasury paper ahead of Alistair Darling's forthcoming Pre-Budget Report.
According to the paper, obtained by The Sunday Times, there will be the one-off charge and the so-called gas guzzlers will also be subject to higher road tax.
More fuel-efficient cars would be eligible for a £2,000 rebate, under the proposals.
Officials apparently acknowledge in the leaked document that the measures would be "presentationally difficult" but argue that they would also "strengthen the environmental signal".
The proposals bear a remarkable similarity to those contained in the Tories' Quality Of Life policy report, which was unveiled by David Cameron this week.