Transport Secretary Grant Shapps has accused Labour’s London Mayor Sadiq Khan of breaking pre-election rules over the announcement of when the Elizabeth line will open.
The Cabinet minister claimed Mr Khan had displayed “breathtaking political cynicism”.
Transport for London (TfL) – which is chaired by Mr Khan – revealed on Wednesday that the capital’s new east-west railway will launch on May 24.
The announcement was made a day before local elections take place in London.
Purdah rules restrict what communications activity can take place in the run-up to an election.
Mr Shapps said: “This announcement is an act of breathtaking political cynicism by the mayor, breaking election rules on such announcements in an effort to garner votes the day before the local elections in London.
“I am therefore immediately referring this breach to the Electoral Commission for investigation.
“Londoners reading this unscrupulous headline grab might like to know that the Government has poured billions into Crossrail to solve delays clocked up on the mayor’s watch, while propping up a transport system hobbled financially by his chronic incompetence.”
Around 30 minutes after issuing the statement, Mr Shapps posted a message on Twitter stating the Elizabeth line will open “thanks to £9bn of Government support”.
He added that it will “transform the lives of Londoners for generations to come and deliver a £42 billion boost to the whole UK economy”.
The total cost of Crossrail – the project to build the railway – has been estimated at £18.9 billion.
Crossrail Ltd says this includes £5.1 billion from the Government.
The Government has also provided nearly £5 billion to TfL to keep services running during the coronavirus pandemic.