The Bank of England looks set to stick to its current programme of government bond purchases on Thursday, but the debate about the right amount and form of future stimulus should remain lively even after the departure of arch-dove Adam Posen.

The Bank is halfway through a four-month plan for 50 billion pounds of gilt purchases to boost the recession-hit economy, and last month Governor Mervyn King said new economic forecasts showed no urgent need for extra stimulus.

Thursday's decision -- announced at 12 noon -- will be the first for new rate-setter Ian McCafferty, who joins the nine-member Monetary Policy Committee from the Confederation of British Industry.

Since the August meeting, a rebound in closely watched business surveys has increased hopes that the economy is crawling out of recession after three quarters of contraction, though the road to a proper recovery still looks bumpy.

"Although inaction is likely at the September meeting, we think that the policy debate on the committee may be particularly intense, reflecting uncertainty and disagreement along two dimensions," said Barclays economist Chris Crowe.

"First, is more easing required? And second, what is the best means of delivering it?," he added.

When the Bank launched the current round of gilt purchases in July, chief economist Spencer Dale and external MPC member Ben Broadbent voted against the extension.

They did not think the inflation outlook had improved enough, and thought other steps to get credit flowing such as the bank's recently started Funding for Lending Scheme could be sufficient.

However, others considered adding even more stimulus at the August meeting.

The market may have to wait until the minutes of the latest meeting are published on September 19 to find out how the debate has shaped up and how McCafferty's arrival influences the discussion.

While observers are uncertain where to place McCafferty on the traditional spectrum of policy hawks and doves, his previous more upbeat comments about Britain's economy make it unlikely that he will demonstrate the same drive for ultra-loose policy Posen showed over his three years as an external policymaker.

Most economists in a Reuters poll expect the Bank to add another 50 billion pounds of gilt purchases to the 375 billion pounds approved so far in November.

The economy has been in recession since late last year, but -- barring a disaster in the euro zone -- the central bank and most other economists see a tepid recovery as inflation falls back towards its 2 percent target.

(Reporting by Sven Egenter; Editing by Hugh Lawson)