Answer
Increases.
Work Step by Step
$E=z_{\frac{α}{2}}\sqrt {\frac{p ̂(1-p ̂)}{n}}$
In order to increase the level of confidence of a confidence interval, we need to increase $z_{\frac{α}{2}}$ because, as $z_{\frac{α}{2}}$ increases, the area under the standard normal curve increases too. And, according to the formula above, as the $z_{\frac{α}{2}}$ increases, the margin of error increases too.
