Apologies in advance for thread drift....
The reason they didn't "give a hoot" about British industry was partly that at the time, the Maritime Industrial Strategy (brainchild of Lord Drayson and his preferred RAND consultant, the wonderfully named Hans Pung) had forced the UK shipbuilding industry to merge/consolidate such that the capacity was sized to build QEC, followed by a steady drumbeat of warships (frigates - FSC/T26 and MHPC), with the occasional biggie thrown in at predictable times a long way downstream. This was the basis behind the TOBA between BAES and the MoD.
The implied assumption throughout the mid-noughties (endorsed by the pollies, MoD and industry), was that you sized the UK shipbuilding capacity to fit the predicted MoD demand for warships and complex auxiliaries. Simple auxiliaries (like tankers, which are primarily a steel box, with a heavily outfitted @rse-end) would go offshore. This was coloured by the experience with the two Waves bought off BAE at the turn of the century for about £150M each.
It took the MoD (specifically the EC(DSR) in town and the DE&S boys) about four years to work out that :
1. There wasn't a suitable OTS ship to meet the requirement (primarily capacity)
2. You couldn't convert a commercial tanker design to meet the requirement (speed, aviation facilities, mil comms and self defence and consequent accommodation demand)
3. You needed to get a competent consultant to design what you wanted and then get a shipyard that was ruthlessly efficient to build the basic ship design, get it to the UK and fit any sensitive bits to it there.
What all this meant was that when MARS tanker was planned and profiled, there was no (recognised) UK capacity to build them (BAES being toppers with carriers). Arguably, A&P Tyne could have had a go as their carrier work wound down, as could Cammell Laird, but neither organisation had built a ship in the last thirty years, so risk through the roof. Mr Harland & Wolff had divested much of his build capacity (vice ship repair) so would have been similarly risky.
Oh and there was no money.
As it turned out, T26 is delayed, which means there's a gap in the steel fabrication demand (see the three OPV for £350M to see how it was filled), which could (only with hindsight) have been used to build a tanker or two. But by then the decision had been made and frankly it would have been painfully expensive.
Thankfully, that competent consultant (BMT DSL) stuck at the task, despite (in fairness to MoD) the funding being continuously deferred to meet the defence main effort and eventually the right result was achieved.
One hopes the same is achieved for MPA....
Thread drift off.