Just seen this on the First Leeds web site:
"
Essential travel
The government advice is to considering (sic) other forms of transport before using public transport and to travel safely. People intending to travel should check the appropriate government advice for the region of the UK they live in.
There are currently no restrictions on passenger type and everyone is welcome on our buses if their journey is necessary, they follow government and First Bus guidance, and they are not feeling unwell. Anyone who is suffering from coronavirus symptoms including a persistent cough or high temperature, should not travel, and should follow public health guidelines.
With operators and customers working together we will provide a bus network, for those who need it, that is safe and allows everyone to complete their essential journeys."
(My underlining)
So somehow they appear to have intepreted "consider other forms of transport" to mean that if you can't travel any other way and you don't absolutely have to travel, you should just stay at home for the indefinite future. I don't think that's what the government had in mind.
So you can use National Express to travel if you like, but you're not welcome on the bus into town to get to the coach station unless you absolutely have to make the journey.
(Or could I argue that given I'm going to travel with National Express and it's too far to walk to the coach station, the bus there
is essential?)