Dear Mr./Ms. Bossname,
I would like to notify of you of my resignation, effective in two weeks’ time, or immediately, whichever is preferable to the company.
During the most recent furlough, I had the opportunity to interview for several jobs. I was ultimately offered a position at one of our competitors. Given the recently history of repeated furloughs and stagnant pay, I feel this is the best move for me and my career at this time.
I have enjoyed my time at the company, and wish only the best for you and my colleagues. I hope that the company is able to overcome the current challenges and become more stable.