The euro remained at its weakest levels of eight months against the dollar early Tuesday, as the single currency continued to suffer negative fallout from France's rejection Sunday of the EU constitution. There is mounting speculation that a Dutch referendum on the constitution will fail Wednesday. The euro was down 1.1% on the session at $1.2336, after touching an intraday low of $1.2309. The dollar was up 0.3% at 108.22 yen.