The collective bargaining agreement reached between Bernie Sanders' campaign and its workers is flush with benefits so generous that political veterans and labor attorneys think it could ultimately turn into an albatross and help sink the Vermont senator's White House prospects.

The contract, which has not been made public but was obtained by the Washington Examiner, allows members of the collective bargaining unit to potentially take up to 57 days of paid leave each calendar year. Employees are entitled to 20 days of vacation after one year, with unused days paid out at 50% at the end of the year; 12 days of sick leave a year; four days for steward training and education; five days of funeral leave, also applicable if a grandparent dies; 11 holidays and two personal or religious days; and 24 hours of school leave, taken in two-hour increments.

"First of all, it seems absurd. Campaigns are 9-5 operations, they’re 24/7. I question the commitment of anyone who joined a presidential campaign and expects to work banking hours," veteran Republican strategist Alice Stewart told the Washington Examiner after viewing the contract. "This contract makes management prohibited from making a lot of decision on the fly, which is necessary on a presidential campaign. The unions are calling the shots. There are certain things that are necessary, but the stipulated time off, stipulated overtime restraints, the stipulated time can work is truly just not sustainable in a presidential campaign. Not to mention the amount of money they’re making and benefits, it’s just not sustainable."

All employees become and remain members of the union on the 31st day of their employment.

"I have read several hundred contracts, and this an excellent contract , " said Kate Bronfenbrenner, a senior lecturer at the Cornell School of Industrial and Labor Relations and an expert in labor relations. "Not only do the workers have excellent benefits specific to their working conditions, they are clearly protected under the contract, including training, which is typically outside the grievance and arbitration process."

Beyond a generous leave policy, the contract also provides numerous protections for members from outside hires, including a provision that contractors and consultants can't be hired to assist the campaign without permission from the union.

"Consultants or temporary employees may be hired to enhance the work of bargaining unit Employees by mutual agreement between the Employer and the Union," the contract reads. Outside hires are also barred from performing "work normally performed with the Union bargaining unit without prior written agreement from the Union."

In the case of layoffs, the Sanders campaign must let go of employees "in order of reverse seniority," meaning junior employees must be the first ones terminated, although they have preference during the next round of hires. All employees, should they be employed for at least one year, are entitled to 30 days of severance at the conclusion of their role.

"Does this mean the Bernie campaign is stuck with a bunch of B-players who have been on the campaign a long time? This is the thing you would find in a teacher’s union, where you can’t lay off senior teachers who might be the worst but have the most protection," said labor researcher Michael Saltsman. "If your point is to construct a campaign around the best people or talent, this is not the way you would do it."

Saltsman also pointed out that the contract mandates, "The Employer will comply with the strongest state and federal laws governing worker safety."

"I assume he hasn't read California's workplace safety rules, which require — among other things — a 68-degree temperature in the bathroom when it's in use. Will bathrooms in Iowa be kept at 68 degrees?" he said.

Members of the collective bargaining unit are also entitled to a $500-a-month deposit into a Medical Expense Reimbursement program for "mental health services." All salaried employees making above $36,000 per year will have 85% of their healthcare premiums covered, whereas employees making $36,000 a year or less, as well as hourly employees, have 100% of their premiums covered by the campaign.

Premiums for life and short-term disability insurance are 100% covered by the campaign.

Should another campaign's workers, such as Massachusetts Sen. Elizabeth Warren's or former Vice President Joe Biden's, enter a union and receive even more generous benefits, members of Sanders' collective bargaining agreement have a "Most Favored Nations" clause, meaning they can immediately enter a new series of negotiations within 30 days.

The contract also lists the wages of employees, with senior members of the campaign only permitted to make three times the salary of the most senior union member, meaning the max salary of the Sanders campaign is roughly $300,000. The lowest-paid employee on the campaign, excluding interns, would be field state staffers at $36,000 annually. The highest paid employee would be bargaining unit deputies to deputies at $100,000 a year.

Union members may not receive a raise, according to the contract, unless "after consultation with the Union."

"The grievance section of this contract is this long list of multiple process and you understand intuitively why a political campaign wouldn’t want a union. You’re hamstrung to keep around low-performing employees or being stuck dealing with grievances," Saltsman said. "A large company might have an entire department dealing with grievances, but a political campaign doesn't. It feels like the campaign is shooting itself in the foot for no other reason than to signal to progressives that he has a unionized campaign."

Potentially hundreds of staffers for Sanders are covered under the provisions of the contract, which was agreed upon in May. The union estimates that up to 1,000 staffers could be in the collective bargaining unit at the peak of the campaign.

In July, the Sanders campaign was hit with a federal labor complaint by an employee who alleged that management had engaged in illegal interrogation, repudiation, and modification of contract.

[ Read more: Bernie Sanders backpedals on scaling back campaign]

