Perhaps the DfT should stop wanting a vote on the 2023 offer and just accept the alternative vote on strick action as the opinion of staff and then move on with this.
Perhaps so, but the bottom line is they are not going to. The last year is stark evidence of this. ASLEF have been trying to stare down a government that is not even looking in their direction.
So the options are simple. One is to stick to the current line and hope that Labour both make a majority at the next election & look favourably on the current dispute & prioritise it over pretty much anything else. At lot of people seem to have nailed their hopes on this, but Starmer has kept himself and his party at arms length from all the various disputes, so I wouldn't be so sure they will be keen on simply handing the unions what they want. In fact if they do get in through by swaying former Tory voters <cough><splutter>*, then they won't want to alienate them too much in the opening period of their administration. Labour isn't the party it once was, where support for unions was the default position.
Alternatively ASLEF could navigate around the current rules (BTW for those people asking if I knew about this, please see one of my first posts on this thread where I reference said rule), its been done before by other unions by simply putting a temporary block on said rule for the purpose of a ballot on the offer. This could be included in that as an initial question to ask if members are happy for the rule to be overridden, and then if they accept or reject the offer. Then the ball truly goes back to RDG / DfT to come back with a better offer. ASLEF could even use this moment to propose an RMT style, no-strings deal that wraps up all the previous years and resets the negotiations to the 2024-25 deal, and gets it's members the backpay I'm sure they'd all be happy to receive.
Of course this option would cost the union for the ballot, but given that a GE is probably still many months away they are almost certainly going to have to re-ballot members on continuing the industrial action, so why not just ballot the offer instead? There quite literally is nothing to lose, and possibly a bit to gain.
(*I'm sure some members of the forum will recognise the irony here)