Please note their is no such thing as a GUARANTEED job, even you if get through selection.
I was instructing at Oxford in September 2001 and within 2 days of the 11th three airline fully sponsored courses(they no longer exist) were cancelled, with something like 60 students with 'guaranteed jobs' up in flames.
Aviation is all about supply, demand & being in the right place at the right time & LUCK. Beware of marketing hype of 'guaranteed jobs and pilot shortage" (the last one was back in 1940!). CURRENTLY there is strong demand and airlines are less selective on who they take on, even BA are looking at direct entry captains, unheard of before - but it won't last forever.
MPL is great if you get selected and you successfully go on to fly for that airline, however left with nothing if you get chopped though. That's why most students (unless MPL 'sponsored') go for the full ATPL (CPL/IR) route as you can potentially go anywhere - assuming the strong demand for ab-inito pilots remain. The MPL courses I am aware of (eg. FlyBe) all do some real flying, including solo & cross-country, though this would be down to each airline.
I would continue down the PPL route and complete it. A few of PPL students who were selected onto a MPL course I instructed on are just finishing their type ratings and should be line flying soon.