The Fed's last interest rate hike will be in December as it faces political pressure due to a weakening economy

• The Federal Reserve's last interest rate hike will be in December, according to investment strategist Louis Navellier.
• Navellier believes a weakening economy will spark tremendous political pressure on the Fed.
• Investors weighed new language in the FOMC statement against Powell's hawkish speech on Wednesday.

The Federal Reserve's final interest rate hike will land in December as Jerome Powell is poised to face "tremendous" political pressure in the face of a weakening economy, according to investment strategist Louis Navellier.

The Fed confused investors on Wednesday, as stocks initially soared after Powell hiked rates by 75 basis points and included new language in the FOMC statement that opened a path to an eventual slowdown on rate hikes. But a hawkish speech from the Fed chief dampened investors' enthusiasm and sent stocks lower.

The new FOMC language said, "In determining the pace of future increases in the target range, the Committee will take into account the cumulative tightening of monetary policy, the lags with which monetary policy affects economic activity and inflation, and economic and financial developments."

Following the statement release, Powell said that he is more concerned about doing too little than too much when it comes to taming inflation, and that current indicators continue to suggest that inflation remains stubbornly high. "It is very premature to be thinking about pausing...we think we have a ways to go."

Navellier said investors should focus more on the FOMC statement than comments from Powell during his press conference. "I want you to know that the FOMC statement is much more important than the Fed Chairman's doublespeak," Navellier said on Thursday.

And as interest rates spike, certain areas of the economy like housing are beginning to weaken considerably, leading to a slowdown in spending and some early signs of job layoffs.

If the economy continues to slowdown, then the Fed is going to face big pressure from politicians in Washington D.C. In a letter on Monday, 11 Congress members including senators Elizabeth Warren and Bernie Sanders expressed concern to Powell about the Fed's aggressive rate hikes.

"If the Fed is going to destroy the US economy, they will come under tremendous political pressure, which they are already feeling, so I expect the Fed will err on the side of caution and cease raising key interest rates after its December FOMC meeting," Navellier said.

That pressure could heat up as the unemployment rate begins to rise from its current level of 3.5%. According to Navellier, a rising four-week average of continuing jobless claims means "it is becoming inevitable that the unemployment rate will rise in the upcoming months and cause the Fed to pause hiking key interest rates."