Labour and the SNP have both claimed they are heading for victory in the Glenrothes by-election, in which voters go to the polls next Thursday.
Labour's Lindsay Roy claimed his party was gaining at the expense of the SNP and that he was "in with a good shout". He added: "I would have said initially I was the underdog but I think things are moving much closer."
But the SNP's Peter Grant said: "The feedback we are getting on the doorsteps is, not only are we on course to win Glenrothes next week, we are on course for a spectacular victory in the independence referendum in 2010."
The claims came on STV's Politics Now programme in which four of the eight candidates in the by-election took part in a head-to-head hustings debate.
Mr Roy, Mr Grant, the Tories' Maurice Golden and the Liberal Democrats' Harry Wills each made a brief pitch and were then questioned in turn.
Mr Roy was closely quizzed on Post Office closures, and at one point told his Tory rival he did not know what a Post Office card account was.
Facing claims from Mr Golden that some suspected a Government decision on Post Office card accounts was being deferred until after the by-election, Mr Roy said: "Can you explain what you mean by the Post Office card accounts?"
Mr Golden told him: "It's how people collect their pensions and benefits from a post office."
But Mr Roy put his SNP rival on the defensive over a letter sent out by Fife council over rises in charges for some home services like community alarms. He challenged Fife council leader Mr Grant to apologise for the "disgraceful" letter.
The eight candidates contesting the by-election on Thursday November 6 are: Morag Balfour, Scots Socialists; Peter Grant, SNP; Maurice Golden, Conservative; Lindsay Roy, Labour; Kris Seunarine, Ukip; Harry Wills, Lib Dems; Louise McLeary, Solidarity; Jim Parker, Senior Citizens' Unity Party.
