M4
Once upon a time (~1997) there was FASH (Future Amphibious Support Helicopter), which in about (2001?) transmogrified into SABR (Support & Amphibious Battlefield Rotorcraft). There were also BLUH (AH7/9 & Gazelle replacement) and SCMR (Lynx HMA replacement)
SABR died in 2004 (ish?) and became FRC (Future Rotorcraft Coherence/Capability depending on who you believe) when "senior people" realised there wasn't enough money in the EP to replace SK4, Puma, Lynx AH & Lynx HMA.
Since then, we've had the Superlynx buy (after they'd decided that they really did have to buy another maritime helo and couldn't just assume that the 42 remaining Merlins could do the job). Sticking plaster fixes (Merlin 3A and Wokka fix to field) will deliver 14 new airframes in two/three years.
Meanwhile, SH hours are going through the roof, SH people are going through the door and Nero in Whitehall is still fiddling.......