The church kick-started its £2.5m 'Inspire!' appeal in March with a £300,000 committment from the parish reserves and had initially targetted reaching £1.5m by the end of 2012.

However, the first six months of the appeal only generated an additional £400,000 in donations, giving a total of £700,000 and leaving the church some way short of its £1.5m 2012 target.

James Irving, the church's finance director, told PrintWeek that the working group charged with leading the fundraising has now revised its target for the year down to the £1m that will be needed to start the most urgent repairs.

"One million pounds means we can confidently begin work that is essential on the structure of the steeple and the spire and on the worst parts of discoloured and insecure stonework in the original walls next spring," he said.

"All the initial work will be external because the internal work is non-essential. We can't work in autumn and winter because of the damp, so if we don't raise this money by Christmas to allow us to start in May 2013 then it will be 2014 before we can start.

"That sort of delay would cast serious doubts on the viability of the structure to remain safe until work could commence."

Irving added that it was "not impossible" to hit the £1m in the short space of time left, thanks in part to the upcoming carol season and a hoped-for influx of corporate donations.

"Where people have pledged money but are unable to donate before their financial year-end in April, we can count that towards the £1m target," said Irving. "So we're inviting lots of big companies that we have relationships with to make a donation this side of Christmas, even if the money won't come in until next year."