The 67 year old, who played Shirley Feeney opposite Penny Marshall as Laverne De Fazio, stunned fans in 1982 when she walked away from the Happy Days spin-off after the second episode of the eighth season, which turned out to be its last.

Reports suggested a growing feud with Marshall contributed to her decision to quit, while others claimed the pregnant actress' outrageous contract demands led to her dismissal from the Paramount Television job.

However, Williams has now set the record straight, alleging she didn't want to leave the show, but felt she had no choice when bosses insisted she work on her due date.

She tells U.S. breakfast show Today, "I had recently gotten married and I was pregnant and I thought I was going to come back and they'd hide me behind benches, couches, pillows, and that wasn't it.

"When it came time for me to sign my contract for that season, they had me working on my due date to have my baby and I said, 'I can't sign this', and it went back and forth and back and forth and it just never got worked out."

Williams and manager-husband Bill Hudson went on to sue Paramount executives for $20 million (£12.5 million). The case was settled out of court and the couple went on to welcome a daughter, named Emily.

The actress admits she was surprised when TV bosses started to accommodate the needs of working mothers on set shortly afterwards, but she has no regrets.

She says, "Right after that they built nurseries on the set and had nannies and everything else for actresses who were pregnant. But I had my beautiful Emily and I was very happy for it."

Williams details her time on the show in her new memoir, Shirley, I Jest!: A Storied Life.