Labor MHA Scott Bacon has confirmed he will resign today.
In an email to thank Labor Party members early on Thursday, Mr Bacon said that after 10 years in politics he had decided "it is the right time to take on a new challenge".
"Firstly I wanted to say thank you," he wrote.
"Thank you for many years of support - be it knocking on doors, phone-calls, putting up posters or just joining me for a laugh.
"I am proud of my contribution to the Parliament, including as a Minister in the former Labor Government.
"Since the Liberals have been in government it's been heart-wrenching to hear from people across Tasmania desperate for a house or a hospital bed. Will Hodgman simply isn't interested in helping every day Tasmanians."
In a media statement, Mr Bacon said his decision to retire was difficult and had not been "made lightly".
"After nearly 10 years in politics, I have decided that it is the right time to take on a new challenge," he said.
"I am proud of my contribution to the Parliament, including as Minister for Tourism and Finance in the former Labor Government.
"I am particularly pleased to have contributed to making Tasmania a true winter tourism destination.
"Ultimately, the most important responsibility of an elected member is to the community and I tried to make sure that my door was always open to people who needed help.
"I have to say, in recent years it has become apparent under this Liberal Government too many people are slipping through the cracks."
Mr Bacon said he would formally resign to the Governor on Thursday.
"I want to ensure the people of Clark have a new representative as quickly as possible. I intend to commence a search for new opportunities in the near future," he said.
Labor Leader Rebecca White described Mr Bacon as a very good friend.
"Scott and I entered the Parliament together in 2010. Not only has he been a very capable Parliamentary colleague and a dedicated local representative, I also count him as a very good friend," Ms White said.
"Politics is a tough business, particularly with a young family, and I fully respect Scott's decision to refocus his priorities.
"Scott was most passionate about representing the people of his electorate. He and his tireless electorate officer Jenni McLeod have assisted thousands of people over the years, often where other service providers and government departments have failed.
"Scott's departure will leave a big service gap in Hobart's northern suburbs."
Ms White said she would be making contact with all of Labor's unsuccessful Clark candidates in the coming days ahead of the recount.
"Labor took a very strong team to the last election and I am confident that whoever is elected to fill Scott's vacancy will do an exceptional job."