Obama administration officials have concluded that the economy, while improved, is still fragile enough that it may need another bout of stimulus. The tax cut could replace the payroll tax cut championed by President Obama in 2011 and 2012, which was designed as a buffer against economic shocks such as the financial crisis in Europe and high oil prices. It expires at year’s end.

The new tax cut could provide hundreds of dollars or more a year to workers and show up in every paycheck. It may be similar to a tax cut Americans received in 2009 and 2010, which provided up to $400 for individuals and $800 for married couples, sources close to the administration said.

The administration’s work on the proposal comes as each presidential candidate is under intense pressure to demonstrate he has the better tax plan. During the campaign, Obama has insisted that he wants to keep taxes from rising for the middle class while increasing them on the wealthy as a way of shoring up the country’s finances.