3/1/2007--Passed House amended. Employee Free Choice Act of 2007 - Amends the National Labor Relations Act to require the National Labor Relations Board to certify a bargaining representative without directing an election if a majority of the bargaining unit employees have authorized designation of the representative (card-check) and there is no other individual or labor organization currently certified or recognized as the exclusive representative of any of the employees in the unit. Sets forth special procedural requirements for reaching an initial collective bargaining agreement following certification or recognition. Revises enforcement requirements with respect to unfair labor practices during union organizing drives, particularly a preliminary investigation of an alleged unfair labor practice which may lead to proceedings for injunctive relief. Requires that priority be given to a preliminary investigation of any charge that, while employees were seeking representation by a labor organization, or during the period after a labor organization was recognized as a representative until the first collective bargaining contract is entered into, an employer: (1) discharged or otherwise discriminated against an employee to encourage or discourage membership in the labor organization; (2) threatened to discharge or to otherwise discriminate against an employee in order to interfere with, restrain, or coerce employees in the exercise of guaranteed self-organization or collective bargaining rights; or (3) engaged in any other related unfair labor practice that significantly interferes with, restrains, or coerces employees in the exercise of such guaranteed rights. Adds to remedies for such violations: (1) back pay plus liquidated damages; and (2) additional civil penalties.