A statement from McPartlin’s publicist said: “Ant has decided to go back into treatment and step down from his current TV commitments.
“He has spoken with Dec and ITV today and asked for time off for the foreseeable future. As such Saturday Night Takeaway will not be going ahead this Saturday.”
An ITV spokesman said: “ITV has taken a joint decision with Ant and Dec’s team not to broadcast Saturday Night Takeaway this weekend.
“We will be reviewing options for the last two episodes of the series (31 March and 7 April) which would not feature Ant who is taking time off to seek treatment.
“We very much hope that he gets the help that he needs.”
The 42-year-old is said to have been involved in a collision with two other cars while driving his black Mini in Richmond just before 4pm on Sunday.
A child passenger in one of the cars – a green Mini – was taken to hospital as a precaution. She is believed to be a three-year-old girl.
Others involved were treated at the scene for minor injuries.
McPartlin failed a roadside breath test and was arrested.
He had been with his mother at the time, according to The Sun.
Pictures of the scene show the front driver’s side of his car smashed in.
A Met Police spokesman said a 42-year-old man had been taken to a south London police station for questioning and enquiries continue.
McPartlin has since been released and reportedly arrived home at 2.40am on Monday.
The Saturday Night Takeaway presenter entered rehab last year after struggling with an addiction to painkillers.
In January, he announced he was divorcing wife and Strictly Come Dancing make-up boss Lisa Armstrong after 11 years of marriage.