TUI Airways has acquired 2 Airbus A321s (SX-ACP, and SX-ABY) which are both Ex-Olympus Aircraft, or as most people know them as, Ex-Monarch. They are due to enter service on Friday 17th May 2019 (6 days from now)
This will be covering the continued MAX8 grounding. As you may know, TUI Airways has also acquired additional leased Boeing 737s to cover this grounding.
Stuart