In what can be described as a blow to chancellor Sajid Javid, the Treasury was on Tuesday (5) stopped from publishing its assessment of nine Labour's policies.
Javid told a meeting of the Cabinet on Tuesday that his department would be publishing a report on the cost of nine Labour policies.
But Cabinet Secretary Sir Mark Sedwell stepped in and stopped the publication after John McDonnell protested the move, reported Politicshome.
A Treasury source told the publication: "This is a very well established process and has been going on since Gordon Brown's time.
"It's a very ordinary thing for the Treasury to look at opposition policies and work out how much they would cost to implement.
"The work has been going on for a good couple of weeks and Sedwill was aware of it - it's not a surprise that it's come up.
"Last week we were talking about how it would be handled and when we were putting it out. But Tom Scholar spoke to John McDonnell on Tuesday morning and he went bananas, saying it was a terrible waste of resources.
"There was then a call between Tom Scholar and Mark Sedwill and Sedwill said no."
Another source added that Javid was unhappy with the move.
Calling it an "embarrassing slap on the face", a senior Labour source alleged that Tory ministers were blatantly use the civil service for party political purposes.
McDonnell had earlier told The Independent that while he was open to anyone analysing Labour's policies, doing it before a general election was an abuse of power.
"It's an abuse of power," he said. "I'm happy for anyone to examine our policies, but to do this hours before a general election campaign is I think an abuse of power. Unacceptable."
From L- Jasvir Singh, MPs Diedre Costigan, Catherine West, Sarah Coombs , Kanishka Narayan, Cllr Sunny Brar and Vidhya Alakeson during the event. 
