The pop act split in 2001, with band members Ian 'H' Watkins and Claire Richards going on to form a duo.
However, Watkins has now confessed that it was Williams who took him to one side and advised him to quit the group.
Speaking on Sky Living's Steps Reunion, H admitted: "We were at Top of the Pops and I was sat on my own in a corridor.
"I remember Robbie came over to me and he put his arm around me and said, 'It's time to leave', and I went, 'Yeah'."
He added: "I don't want to feel like that again. I want this group to be a part of my life and enhance it, not damage it."
Steps topped the UK album chart on Sunday with their hits compilation The Ultimate Collection.
The 'Tragedy' singers have added six extra arena dates to their 2012 'Ultimate Tour' after the initial batch of tickets failed to meet overwhelming demand.
Steps Reunion airs on Wednesday nights at 9pm on Sky LIving.
Watch Digital Spy's recent interview with Steps below: