US Secretary of State John Kerry begins the sales push of his life this week as he tries to stop Congress from wrecking what supporters hail as his crowning diplomatic achievement.

America's top diplomat is expected to defend the Iran deal before both the House and Senate foreign affairs panels, although neither hearing has been publicly notified yet. Expect him to be flanked by Treasury Secretary Jack Lew and Energy Secretary Ernest Moniz, who has emerged as one of the most trusted administration sources on Capitol Hill, to provide the details.

Wendy Sherman, the undersecretary of state for political affairs who was a key player in the negotiations, will also be back on Capitol Hill selling the deal as soon as July 20, according to the State Department's daily schedule. The appearances are part of a full-court press by the administration that includes personal lobbying on Capitol Hill by Vice President Joe Biden and an upcoming visit to Israel and Saudi Arabia by Defense Secretary Ash Carter.

The administration has its work cut out as it tries to prevent the House and Senate from assembling a veto-proof majority over the next 60 days for legislation that would bar the White House from lifting statutory sanctions on Iran and potentially kill the deal before it even goes into effect. Already, more than 170 House members have signed on to a resolution of disapproval from the co-chairman of the House Republican Israel Caucus, Rep. Peter Roskam, R-Ill., while the pro-Israel lobby American Israel Public Affairs Committee is now officially urging lawmakers to reject the deal.