PM warns forces chiefs over lobby campaign

· Plea to back 'hard power' fight against terrorism
· Successor could be under pressure to reduce UK role
Britain's fragile public support for interventionist military action is being put at risk by the lobbying of armed forces chiefs about money, equipment and the over-stretch of resources, Tony Blair warned yesterday.

He said his political successors would be under huge pressure to pull back into a more limited peace-keeping role, a change that he said would"horrify" the armed forces and prove "catastrophic" for Britain's world power.

Mr Blair also urged his probable successor Gordon Brown, not to take the easy option, but continue with a role for Britain backed by long term increases in spending on "equipment, personnel and conditions of our armed forces".

The call for long term extra spending, including a massive ship building programme may irritate the Treasury. Mr Brown has shown a determination to fight the terrorist threat at home but some have questioned whether the Iraq debacle will lead him to adopt a foreign policy based on a more narrow definition of the national interest.

In a question and answer session following his speech on HMS Albion, in Plymouth, Mr Blair insisted he was confident that Mr Brown shared his view of the role of the army.

The theme of the prime minister's speech was that Britain needs to be able to continue to project "hard power" if the terrorist threat is to be defeated, and to maintain an international lead on "soft power" issues such as climate change, Africa and diplomacy. He argued that to retreat in face of the terrorist threat would be catastrophic, merely postponing rather than averting eventual confrontation with anti-western elements of Islamism.

His officials indicated that his key concern was to find a new covenant between politicians, public opinion and military. The covenant is necessary the in face of new kinds of war, growing global demands, the destabilising effect of war images broadcast around the world, and the breakdown of military hierarchies through websites such as Liveleak.

Mr Blair privately fears that the military chiefs, by their recent high profile questioning of the extent of Britain's overseas commitments, as well as the quality of equipment or accommodation, are undermining the instinctive support within the military for tough war fighting. "The military, and especially their families, will feel they are being asked to take on a task of a different magnitude and nature. Any grievances, and issues to do with military life, will be more raw, more sensitive and more prone to cause resentment."

As a result, he said: "Public opinion will feel divided, feel that the cost is too great, the campaign too long and be unnerved by the absence of victory in the normal way they would reckon it. This impacts on the feelings of our armed forces. They want public opinion not just behind them, but behind their mission. They want the people back home to understand their value, and not just their courage".

He said the risk in Britain and the US was that "politicians decide it's all too difficult and default to an unstated passive disengagement" so that "doing the right thing slips almost unconsciously into doing the easy thing".

Without any conscious strategic decision British armed forces will have slipped into a peacekeeping role, he warned."The irony is that the one group of people who I am sure would not want this to happen, are our armed forces."

He argued his choice for the future British defence posture is one in which armed forces are prepared to be war fighters as well as peacekeepers. At the same time, foreign policy must be based on strong alliance with America and a willingness "to project strong, as well as soft, power and for us to be as willing to fight terrorism and pay the cost of that fight wherever it may be, as we are to proud champions of the causes of peace in the Middle East or action against poverty". He called for a long term increase in defence spending and said the government's record on military spending was far better than the Conservatives, rising annually in real terms by 1.4% in the three years since 2004.

He acknowledged the strain the forces were under, fighting twin campaigns in Iraq and Afghanistan. "It is true that operational commitments are at a higher level than originally planned. Service personnel are working harder and for longer than intended."

The shadow foreign secretary William Hague dismissed Mr Blair's call for a debate. "This is yet another episode of Ten Wasted Years by Tony Blair," he said.