WASHINGTON — The August congressional recess could prove to be a rocky period for some Democrats who will face constituents questioning them about why the Obama administration struck a nuclear deal with Iran.

Pro-Israel lobbying groups like the American Israel Public Affairs Committee will be using the time to urge lawmakers to vote against the deal when they return to Congress after Labor Day weekend.

“We are engaged in a major bipartisan educational and lobbying effort against the deal and for a better deal — this includes grassroots contacts with Members of Congress, lobbying in Washington and supporting the efforts of Citizens for a Nuclear Free Iran,” an AIPAC source told The Daily Caller, noting that AIPAC has a major lobbying effort in Washington this week and their members will be meeting with their Senators and Representatives in their respective states and districts during the recess.

Most Democratic members of Congress, particularly those with heavily Jewish districts as well as donors, are staying quiet about whether they will vote for or against the nuclear deal with Iran.

Following Secretary of State John Kerry’s testimony to the House Foreign Affairs Committee Tuesday, the Committee’s ranking member, New York Rep. Eliot Engel told reporters he is undecided as to which way he will vote on the agreement.

Kerry would not say how he or the president would react if Congress voted to override a presidential veto and rejects the deal.

“You strongly do not want us to override a presidential veto, but if we do, that triggers certain American laws,” California Rep. Brad Sherman asked. “I’d like to give you an opportunity — you don’t want us to do it, you think it’s terrible policy, you think the rest of the world would be against us — but let’s say Congress doesn’t take your advice, we override a veto. And the law that’s triggered then imposes certain sanctions. Will you follow the law even though you think it violates this agreement clearly and even if you think it’s absolutely terrible policy?”

“I can’t begin to answer that at this point without consulting with the president and determining what the circumstances are,” Kerry responded.

Sherman then asked, “So, you’re not committed to following the law if you think it’s a bad law?”

“No,” Kerry responded, “I said I’m not going to deal with a hypothetical, that’s all.”

“[The hearing] doesn’t help you move in one-way or another. What it does do is let the administration understand that some of us have questions that really need to be addressed,” Engel said. “We know that a lot of this deals in hypotheticals, because people who think we should turn down the deal think we have a chance to do something better if the deal was turned down. And the administration, of course, rejects that and says that if a deal is turned down, that’s it. You lose the sanctions. You lose not only the sanctions, the international coalition breaks apart.”

He later said, “My major problem that I’ve asked questions about is that this deal, in essence, in 15 years legitimizes Iran as a nuclear threshold state. It really enables them to have highly enriched uranium and produce it without any kind of restrictions. I would have liked it better if Iran was not permitted to do that.”

Engel, whose Westchester County, N.Y., district includes a large Jewish population, said that his office receives regular phone calls from constituents urging him to vote against the deal.

“My calls have been against the deal — many more against the deal than for the deal, but I’ve been around this place for a long time — 14 terms. I haven’t always gone along with tallies. You have to, in your own mind, decide what’s best for the country. That’s the bottom line, and that’s what I’m going to do. Now I will say that a lot of concerns of my constituents have and they articulated it to me, I also have those concerns.”

Democratic New York Rep. Carolyn Maloney is also undecided and said she is still listening to all the experts on the issue.

“I just had a slew of them in my office. I’m studying the material and I’m studying everything,” she said.

DNC Chair Debbie Wasserman Schultz told CNN she is also undecided, while California Democrat Juan Vargas wrote an op-ed in the San Diego Union Tribune last week denouncing the deal and opposes it completely.

“Rather than demand Iran’s bad behavior be corrected, this agreement rewards it,” Vargas wrote. “In Iran, they’re calling the coming payday a ‘nuclear feast.’ And we know what the main course at that feast will be — terrorism. Iran has spent decades directing and funding terrorism against the United States and our allies.”

“Supporters of this agreement believe that relieving sanctions and legitimizing this regime will moderate them,” he continued. “That didn’t work with North Korea, and it won’t work with Iran. This strategy is doomed to fail, and this deal is destined to be remembered as a mistake.”

Democrats in the upper chamber are also getting pressured from constituents about the Iran agreement. Senate Armed Services Committee member Dick Blumenthal told TheDC he has been contacted by “many” of his Connecticut constituents.

“I am still reviewing very closely the documents and meeting with experts as well as administration officials and opponents. I am concerned about a number of different areas of the agreement and also what the alternative is,” he said.

Senate Foreign Relations Committee ranking member Ben Cardin, co-author of the Corker-Cardin Iran nuclear bill is undecided on which way he’ll vote on the Iran agreement. Cardin, however, criticized the administration for taking the deal directly to the United Nations before allowing Congress to review it.

“I expressed myself openly by letter with Sen. [Bob] Corker. I thought they should have waited. There was no downside in waiting. The UN doesn’t take effect for 90 days. They should have waited until the Congress acted. Having said that, I don’t think it affects out consideration,” the Maryland Democrat told TheDC, noting that the 24 day potential delay for undeclared sites still concern him.

Senate Foreign Relations Committee member New Jersey Rep. Bob Menendez is one of the few outspoken Democrats who told TheDC that it was clear the administration told the public that anytime and anywhere inspections was part of the negotiations with Iran.

“I heard many times from different administration witnesses—anytime anywhere. So to me that was pretty crystal clear and obviously the procedure that has been set up is not anytime anywhere,” he said.

Secretary Kerry is expected to testify on the Iran nuclear deal before the Senate Armed Services Committee on Wednesday.