Thousands of Bosnian Serbs have protested against Mr Karadzic's arrest
Serbia's war crimes court is still waiting for delivery of the appeal by former Bosnian Serb leader Radovan Karadzic against his extradition.
Mr Karadzic's lawyer says he posted the appeal at the last minute, from a remote post office in Bosnia, trying to delay the process as long as possible.
Officials in Belgrade said the document had still not arrived on Monday.
"I wouldn't rule out that my appeal grows a beard and moustache before it gets here," said Mr Karadzic's lawyer.
Svetozar Vujacic said he wanted to prevent his client's extradition before a pro-Karadzic rally scheduled for Belgrade on Tuesday evening - but that the authorities were determined to transfer him before then.
"They are using all illegal means to try send him to The Hague before the rally," Mr Vujacic said, according to the AP news agency.
Under Serbian law, all Mr Karadzic, 63, needs is proof that his appeal was posted before the deadline and the court must simply wait for it to arrive.
A Serbian panel of judges has three days to decide on the merits of the appeal before they issue a final order on extradition.
He is unlikely to be transferred to The Hague until Wednesday at the earliest, correspondents say.
Radovan Karadzic faces genocide charges in connection with the Bosnian war from 1992 to 1995. He was arrested in Belgrade on Monday after nearly 13 years as a fugitive.
Mr Karadzic had been living in Belgrade and working as an alternative therapist under the assumed named of Dragan Dabic. He had grown a long grey beard and ponytail.
Mr Karadzic led the formation of a separate Bosnian Serb assembly in 1991 - one of the sparks that ignited the 1992-1995 Bosnian war.
He has been indicted for crimes against humanity and genocide over the massacre of up to 8,000 mainly-Muslim Bosniaks at Srebrenica in 1995.
He has also been charged over the shelling of Sarajevo, and the use of 284 UN peacekeepers as human shields in May and June 1995.
His colleague, former military commander Ratko Mladic, remains at large.