A group of 17 conservative organizations wrote an open letter to members of the House of Representatives on Tuesday encouraging them to continue to try to delay the individual mandate.

The organizations, which include Americans for Tax Reform (ATR) and Freedom Works, note that the Obama administration delayed the implementation of the employer mandate on July 2 but left the individual mandate in place.

"While it is highly questionable whether the Obama administration has the legal authority to delay the employer mandate, their admission that the Obamacare law is unworkable is all too accurate," the groups wrote.

"Unfortunately, this accommodation was provided only for Big Businesses," they continued. "We believe that individuals, small businesses, and families deserve at least the same reprieve from Obamacare’s costly mandates."

ATR’s Ryan Ellis noted that the individual mandate will apply to some small businesses, like sole proprietorships, as well as individuals and families who do not receive an exemption.

"Thus, there’s a deep injustice in giving an (illegal) reprieve to large businesses (the employer mandate applies to firms with [more than] 50 employees), but not to small businesses (most of whom have no or very few employees, and are struggling)," Ellis wrote in an email.

"That’s to say nothing of the deep injustice of giving a big business this indult while hanging ordinary families out to dry by still subjecting them to their own individual mandates," Ellis continued.

The administration’s delays, announced the week of July 4, have created a firestorm around the law and raised concerns about its viability as it heads toward full implementation this fall and next year.

Both chambers of Congress have called for the law’s delay. All 46 Senate Republicans signed a letter to President Barack Obama on July 10 calling for the law to be permanently delayed, while the GOP leadership in the House sent a letter to Obama the day before inquiring into the delays and asking that the individual mandate be delayed as well.

Several House committees are holding hearings on Wednesday and Thursday to examine the delays and their implications.