WASHINGTON – The White House is dramatically expanding its efforts to sell the Affordable Care Act, hiring additional staffers, formulating a public-relations strategy and reaching out to key lawmakers as the new health insurance system prepares to launch in coming months.

The administration’s push comes as Republican leaders signal their intent to focus on the law’s implementation, and any problems it encounters, in their quest to retake the Senate and maintain their House advantage in 2014.

GOP lawmakers announced Tuesday that they will hold hearings on the administration’s decision to delay the law’s requirement that large employers provide health care coverage for workers. House Speaker John Boehner, R-Ohio, also vowed to hold a House vote this month to delay key elements of the law.

The White House and its congressional allies, for their part, are attempting to minimize problems as the law reaches a critical stage. White House Chief of Staff Denis McDonough spends at least a couple of hours a day working on implementation, regularly reaching out to congressional Democrats to see what questions they need answered to spread the word about the law back home, according to several people involved in the discussions.

The administration is holding a Google hangout Wednesday to promote its enrollment website, and by the end of the week, it will announce at least two new White House appointees who will work on so-called Obamacare, including Chris Jennings, President Bill Clinton’s former chief health care policy adviser.

The recent announcement of the delay in a requirement was hailed by Rep. Robert Andrews, D-N.J., who praised the White House for “listening to practical problems and … trying to address them and solve them.”

But Rep. Tim Murphy, R-Pa., said the law is “simply not ready” to take full effect in October.