From Gallup:

Amid the government shutdown, 60% of Americans say the Democratic and Republicans parties do such a poor job of representing the American people that a third major party is needed. That is the highest Gallup has measured in the 10-year history of this question. A new low of 26% believe the two major parties adequately represent Americans.

And how does the data break out in terms of political parties?

Republicans (52%) and Democrats (49%) are similar in their perceptions that a third party is needed. In fact, this marks the first time that a majority of either party’s supporters have said a third party is needed.