The chances of further Bank of England economic stimulus are likely to remain hanging in the balance on Wednesday, when the central bank publishes details of its April policy decision against a backdrop of unexpectedly stubborn inflation.

Economists will scrutinise the minutes of the Monetary Policy Committee meeting for hints that the Bank might extend its quantitative easing programme next month, when the 50 billion pounds of gilt purchases approved in February will be complete.

Most economists doubt there will be more QE beyond the total 325 billion pounds already approved, although they expect April's minutes to continue to show two external members, Adam Posen and David Miles, voting for an increase to 350 billion.

There's a significant risk that they could do more, but I don't think they have seen enough of a downside surprise to do more in May, as the inflation backdrop still looks pretty concerning, said Allan Monks, a UK economist at J.P. Morgan.

Overall, the economic outlook has improved since February.

But weaker than expected factory output data released the same day as the April 5 policy decision raised concerns that Britain might have slipped back into recession.

In addition, tensions in debt markets on the euro zone periphery have worsened.

So any suggestion that the nine-member MPC was starting to seriously question the moderate underlying growth that it forecast in February might point to more QE next month.

However, a more pressing concern in the view of many economists is the failure of inflation to fall quite as fast as the Bank forecast. Oil prices rose sharply in February and plateaued thereafter, causing annual inflation to increase in March for the first time in 6 months.

Posen told reporters after the release of the inflation figures on Tuesday that one month's data was not enough to change his view on policy, but that the Bank would have to think again if core inflation did not show a sustained fall.

When you read the minutes tomorrow you'll see we are very aware of that, he said.

One area where this concern might show up is in the Bank's analysis of slack in the economy as a whole, and particularly the labour market - something that since the start of the financial crisis has fed into its forecasts of an inflation undershoot over the medium term.

Last month the Bank minutes warned that unemployment might cease to keep a lid on wage inflation if the rise in oil prices persisted. Any strengthening of this language could point to higher inflation forecasts, putting a stop to further QE.

(Editing by Hugh Lawson)