Vladimir Putin could launch a direct attack on Britain as his war in Ukraine falters, Labour MPs were warned last night amid questions over when Keir Starmer will unveil plans to increase defence spending.Former Nato leader and defence secretary Lord Robertson used a meeting of the parliamentary party to warn the 'cornered' Russian dictator could lash out at Britain.Robertson, who led a review of the state of our Armed Forces last year, said that Ukraine was gaining the upper hand against Russia, and while the frustrated autocrat would not attack the US, we could be in his sights.The peer has previously warned that Russia could use cruise or ballistic missiles against the UK, while ministers reportedly also fear it could target undersea cables or launch a debilitating cyber attack.It comes amid confusion over the state of the Defence Investment Plan (DIP). Ordered more than a year ago and due to be published last autumn, ministers are still arguing over the scale of increased funding and where it should come from.The BBC reported that it could be unveiled on Thursday this week, but it is understood this is possible but optimistic and next week is now more likely. Sir Keir, who has said he will reveal DIP before a Nato summit in July, and Chancellor Rachel Reeves are reportedly arguing for a £15 billion package, far short of the £28 billion over the next four years which defence officials have called for. The PM is said to want to announce £6bn funding for the Global Combat Air Programme, a joint stealth fighter programme between the UK, Italy and Japan. Former Nato leader and defence secretary Lord Robertson used a meeting of the parliamentary party to warn the 'cornered' Russian dictator could lash out at Britain Robertson, who led a review of the state of our Armed Forces last year, said that Ukraine was gaining the upper hand against Russia, and while the frustrated autocrat would not attack the US, we could be in his sights. The PM is said to want to announce £6bn funding for the Global Combat Air Programme, a joint stealth fighter programme between the UK, Italy and JapanAt the same time, ministers have reportedly agreed to plough £250million more into the Ajax programme, a light tank for the British Army which is over budget, late and which leaves soldiers ill after using it due to noise and vibrations.The Financial Times reported that the deal for the Welsh-made armoured vehicle would take its total programme cost to more than £1billion. Labour's Strategic Defence Review was published in June last year and promised an end to the 'hollowing out' of the UK's armed forces. But the investment plan to follow has still not been released. The DIP is to set out how the UK will increase its defence spending from around 2.6 per cent of GDP to 3 per cent by the end of the decade and 5 per cent by 2035.Earlier this year Lord Robertson, who is an adviser to US defence lobbying firm the Cohen Group, accused Sir Keir of leaving Britain 'unsafe' through 'corrosive complacency'. In a devastating assessment, he warned the Government was prioritising 'the ever-expanding welfare budget' over essential security. The peer - who helped write Labour's Strategic Defence Review last year - was backed by military chiefs who said the UK could no longer rely on the 'US cavalry coming to bail us out'. They insisted America was right to ridicule the 'big bad' Royal Navy as it was 'too small' to be effective. ministers have reportedly agreed to plough £250million more into the Ajax programme, a light tank for the British Army which is over budget, late and which leaves soldiers illThe Defence Secretary will outline plans to ensure more defence spending stays within the UK amid ongoing wrangling over the long-awaited Defence Investment Plan.The Prime Minister and Chancellor are reportedly arguing for a £15 billion package, far short of the £28 billion over the next four years which defence officials have called for.Speaking at the GMB Union's congress this afternoon, Mr Healey will announce plans to favour British-based defence companies, according to the Times.According to an excerpt of his speech shared with the newspaper, Mr Healey will say: 'The Government will develop a new approach that looks to give credit in future defence contract decisions to British-based companies based on a genuine, substantive presence in Britain and long-term commitments to British communities and British supply chains.'As part of this drive, I can announce I will make greater use of national security exemptions for defence contracts — which allow the Government to require certain capabilities to be built in Britain — supporting our UK industrial base and your members' jobs.'We will ensure that, in large defence contracts, there are provisions to require any significant sub-contracts to be placed with UK-based companies, or guarantee competitions so UK competitors aren't shut out.'Defence contracts 'sent overseas' will require jobs to be created in the UK under Mr Healey's plans, the Times added, with the Defence Secretary insisting that his approach is 'unashamedly pro-Britain'.