The "battle bikes" fanned out from Westminster yesterday to launch the Green Party's election campaign. Compared with the helicopters and motor cavalcades favoured by the major parties, this public reliance on pedal-power was characteristically quirky and refreshing. But it also jogged our memory.

The "battle bikes" fanned out from Westminster yesterday to launch the Green Party's election campaign. Compared with the helicopters and motor cavalcades favoured by the major parties, this public reliance on pedal-power was characteristically quirky and refreshing. But it also jogged our memory.

When did we last hear the Prime Minister pledging to place climate change, along with Africa, at the top of his international political agenda? When did we last hear him describe it - as he did last autumn - as one of the greatest challenges facing the planet? And how long ago was it that the Government's chief scientist, Sir David King, described global warming as a greater threat to the world than international terrorism?

Through the protracted pre-election skirmishing until now, we have heard not a whisper from either the Prime Minister or the Labour Party about the place they intend to allot to the environment in their election platform. We find this surprising, not to say profoundly disappointing.

We have heard much about the economy, about taxation and about the miracles wrought by the Chancellor. We have had select details of the manifesto dangled before us, including further reform of the health service, more money for child care and help for the multitude of "hard-working families". Much of this amounts to technocratic tweaking designed to block off areas where the Opposition might be perceived to have an advantage. There was nothing in the visionary, big-picture department and nothing that might come under even the broadest definition of "environment".

This does not mean, of course, that the environment will not feature in Labour's manifesto. We are confident that it will. Last year, Mr Blair promised that a list of green policies would be included in the manifesto - and we have no reason to doubt that. Then, two months ago, there were reports that Labour was considering an election commitment to impose tougher penalties on companies and individuals who pollute the environment, with stiff fines imposed on offenders along with the obligation to clean up the mess. The fact that we have reached this point in electoral hostilities without hearing more, however, strongly suggests that the Prime Minister is not treating the environment as the priority he led us to believe it would be not so many weeks ago.

The risk now is that the promised list of green policies in the manifesto will amount to a mere formality: fine words designed to establish the party's green credentials in voters' minds, but words without the benefit of the money and the will that would allow them to be translated into action. There must also be the suspicion that some of the Government's green-tinged zeal, at least on climate change, has a political motivation not unconnected with Iraq. Global warming and what to do about it was one of the few areas in which the British government could really separate itself very publicly from George Bush. There may also have been the calculation that a strong stance on green issues might woo back some of those voters angry about the Iraq war.

This is why the Government's next proposals on the environment need to be judged in the light of its record. For all its stated good intentions, this Government has not been as green as it often likes to boast. Initial cuts in emissions largely reflected the switch in power generation from coal to natural gas; emission levels have changed little during Labour's second term. The Government may be on course to meet its commitments under the Kyoto Treaty, but is now unlikely to meet the more ambitious targets it set itself for 2010. It has been wary of introducing new ecological requirements for cars, sent contradictory signals about road-building versus public transport, and has not addressed the environmental challenge of increased air traffic.

It has fallen short on two fronts simultaneously - on the necessary action and on the broader vision. Its manifesto commitments should be scrutinised with care.