SUGAR LAND, Texas -- Supporters of U.S. Rep. Tom DeLay heckled Democratic candidate Nick Lampson Thursday as Lampson called for the congressman to immediately resign, KPRC Local 2 reported.

A group of about two dozen DeLay supporters yelled and carried signs outside Sugar Land City Hall at a 10 a.m. news conference called by Lampson, who demanded the outgoing congressman formally resign so that voters can choose their new representative during a special election on May 13.

DeLay, who is under indictment in Texas on charges of criminal conspiracy and money laundering, announced Tuesday that he would resign sometime before mid-June.

Lampson, who lost his seat when DeLay redesigned the state's congressional districts in 2004, called on Perry Thursday to set a May 13 special election so the district would be represented after DeLay leaves, and asked that DeLay vacate his office by Friday.

Gov. Rick Perry said Thursday he would not call an emergency special election to replace DeLay, meaning candidates for the suburban Houston congressional seat will have to wait for the November election.

"If I don't get (DeLay's letter of resignation) by close of business tomorrow, the election will be in November," Perry said Thursday.

Perry has the authority to call an emergency special election anytime or wait for the next uniform election date, which is May 13. DeLay would have to resign this week for a May election. After that, the next election date is Nov. 7.

Lampson's Thursday morning news conference turned into an anti-Lampson rally, where protesters waved signs that told the Democratic candidate to go back to Beaumont, an area he used to represent in Congress.

DeLay's supporters were encouraged to disrupt Lampson's news conference by DeLay's campaign staff -- via an e-mail advisory. The e-mail came from DeLay campaign manager Chris Homan. It read, "Let's give Lampson a parting shot that wrecks his press conference." Homan said he organized the protest through phone calls and e-mails, but DeLay didn't know about it.

The Democratic candidate's supporters said the outgoing congressman's plans to move to Virginia, which would make him ineligible to run in the 22nd Congressional District race, lack formal resignation, and that his plans to stay in office until June are a stall tactic.

Lampson's campaign manager, Mike Malaise, said the rally was a tactic to intimidate the opposition.

"It would not cost the taxpayers extra money, and it would avoid a situation where the people of this district are without representation for several months at a time, which, if we go past this May 13 date, could be the case and most likely would be the case," Malaise said.

Political experts said that when the special election is held is important because a longer campaign would give a new Republican nominee more time to talk to voters.

A committee of Republican precinct chairmen from the four counties that comprise the 22nd Congressional District will choose a new GOP candidate.

Potential candidates include:

Harris County Judge Robert Eckels
Sugar Land Mayor David Wallace
State Rep. Robert Talton, R-Pasadena
State Rep. Charlie Howard, R-Sugar Land