In the 1996 elections, Slomiansky was placed 10th on the National Religious Party's list of candidates. He entered the Knesset in May 1997, following the death of Avraham Stern. He lost his seat in the 1999 elections, but regained it in 2003 when he was placed sixth on the party's list of candidates. He was later re-elected to the Seventeenth Knesset in 2006. During this period, he set a record for being the only member of Knesset to be present for 100% of the meetings and votes; likewise, he was known for being an extremely prolific legislator.