Three U.S. senators are warning of a “disastrous rupture” in relations with Egypt if the case of 19 Americans charged with illegal fundraising is not resolved soon.

Republicans John McCain and Kelly Ayotte and independent Joe Lieberman said Tuesday that congressional support for Egypt, including financial aid, is in jeopardy.

The senators say those inside the Egyptian government who oppose relations with the United States are exacerbating tensions and inflaming public opinion. But they say there are people of goodwill in both countries who are working hard to resolve the crisis.

Egypt says 43 activists, including 19 Americans, who were working with non-governmental organizations will be put on trial on charges of illegally funding pro-democracy groups. One of the Americans is Sam LaHood, son of Transportation Secretary Ray LaHood.

The U.S. State Department says the Americans and others were working to support Egyptian elections. It says they are completely non-partisan and were not raising money to support any individual candidate.

Egypt is preparing for a presidential election aimed at replacing the interim military government with a democratically elected civilian administration. Parliamentary elections were held last month.

Thousands of Egyptians have protested, demanding a faster transition to civilian rule. Egypt has been under a military government since President Hosni Mubarak was ousted by a popular uprising last year.