Small-business confidence tumbled in October, as companies became even more concerned about Washington gridlock, a key industry advocate said Tuesday.

The National Federation of Independent Business (NFIB) said its small business optimism index fell to 91.6 in October, a month when the federal government was partially shut down roughly half the time. The index had stood at 93.9 in September, and hasn’t been this low since the months after Washington’s showdown over the fiscal cliff.

After the stalemate, NFIB said almost seven in 10 small-business owners aren’t interested in expanding right now, with more than half of them blaming Washington.

The small-business advocate, which challenged the constitutionality of President Obama’s healthcare law to the Supreme Court, also blamed the flawed rollout of the law for the drop in small business optimism.

“Washington paralysis is never good news for the economy, so it was no surprise that while politicians were arguing over whether or not the government should remain fully operational, small-business optimism measures deteriorated,” NFIB’s chief economist, Bill Dunkelberg, said in a statement.

“Small employers are not fooled by headlines announcing record high stock market indices; everyday they live the economic realities of overregulation, increased taxes, weak sales and a government without any direction or plan for the future.”

In all, seven of the index’s 10 components dropped in October, with fewer small-business owners expecting the economy to improve or for sales to get higher.