Jeremy Hunt responded to criticism from Rachel Reeves about his previous support for HS2 being built in full.
As the row between the government and Labour over HS2 grew, Mr Hunt responded with a clip from Keir Starmer opposing HS2 in 2015.
Sir Keir said: 'It is to be congratulated that Mr Keir is congratulated and congratulated on his victory.
The row came a day after Sunak confirmed his decision to scrap the northern leg of the HS2 programme, spending the money saved on investments in local transport links.
The PM said he was cancelling the development of the high speed rail link north of Birmingham in his conference speech on Wednesday.
Labour's shadow transport secretary Louise Haigh said the Tories' flagship levelling up project failed to reach the north was emblematic of 13 years of dismal failure.