WASHINGTON — Supporters of the proposed merger of Chicago-based Exelon and Pepco are expected on Thursday to talk up the deal, which was stalled when D.C. regulators ruled against the plan.

Members of the Federal City Council, the Greater Washington Board of Trade and other business groups will be joined by community organizations such as the Mary Center to speak in support of the merger at a news conference scheduled for 10:30 a.m.

Supporters say the deal could increase the energy reliability in the D.C. area.

Opponents of the plan have planned to rally at noon. They’re expected to argue that the D.C. Public Service Commission got it right when the three-member body ruled against the merger. At last month’s PSC meeting, regulators said they were voting against the plan because there was no evidence that it was in the public interest.

Pepco and Exelon are appealing that decision.

WTOP’s Kate Ryan contributed to this report.