I think that it will reach £3 a litre, just because prices go up. Prices are set at the a level most people are prepared to pay. If no one bought it they would go out of business so prices tend to match demand.
When I started driving petrol was 33p a gallon. When a 1p a gallon increase was announced in the budget long queues would almost immediately appear at fuel stations, some people only managing to get a gallon or two into already almost full tanks! These days we just moan and continue to fill up because most of us are able, just, to afford it. I imagine, however, that a lot less driving around just for fun is done these days compared to my time.