The AFL-CIO live-tweeted President Barack Obama's speech earlier Tuesday at the labor union's annual convention in Pittsburgh.

The union's thread became very popular on Twitter, with the hashtag #aflcio climbing into the ranks of Twitter's trending topics for a period of time.

Before an enthusiastic crowd, President Obama expressed support for the Employee Free Choice Act (EFCA) and the public health insurance option, two legislative issues the labor movement strongly supports.

Sen. Arlen Specter (D-Pa.) also appeared at the convention, predicting that a labor-friendly version of EFCA would pass before year's end. In a floor speech earlier this year, when he was still a Republican, Specter said he would not support the bill.

Here are some highlights from the live tweet:

Obama: "I stand behind the Employee Free Choice Act" #aflcio09 #efca

Obama: there needs to be a public option! #aflcio09

Obama: I refuse to let America go back to the greed and irresponsibility that caused the economic crisis #aflcio09

Specter: we're going to pass an Employee Free Choice Act that satisfies the principles you've laid out #aflcio09 #efca

Specter: "long past due to have labor law reform" #aflcio09