Day-to-day transport spending could be increased by Labour or the Lib Dems by 2020

The Institute of Fiscal Studies has spelt out the implications of the four biggest parties' manifestos for transport as a department not protected from spending cuts.

The plans range from an average 18% cut to unprotected departments from this year to the end of the Parliament if the Conservatives were to rule alone, to an overall 4.4% increase over the five years under Labour.

The Liberal Democrats would also spend more on unprotected departments such as transport, but only by an average of 0.8% over the course of the Parliament - and assuming that they manage to "balance the books" by 2017/18. The SNP, in contrast, despite what the IFS described as its "anti-austerity rhetoric," would cut unprotected departments by 2.5% over the lifetime of the Parliament, increasing spending on social security payments instead.

The IFS said that the main political parties had "not been transparent about where their cuts would fall, with the exception of the Liberal Democrats, who have spelled out plans up to 2017/18". 

Their analysis highlights that, even under the Conservatives' plans, departmental spending would only fall to its 2004/05 level. However, it points out: "If the Conservatives are not able to implement the full £12 billion of cuts to social security spending that they want to achieve, then either they would have to increase total spending, or the cuts to departmental spending would have to be larger than described here". 

The IFS is also critical of Labour, saying: "It looks like Labour might need only relatively small cuts to unprotected departments on top of the cuts already in place for 2015/16 to bring about a balance on the current budget by 2018/19... we can only say 'looks like' as Labour's pledge to 'get a surplus on the current budget' is vague".