The top law enforcement officers from six states have urged the Surface Transportation Board to reject Union Pacific and Norfolk Southern's revised merger application due to concerns over its completeness.
A letter signed by Montana Attorney General Austin Knudsen and other attorneys general from five other states highlights the need for a more thorough review of the proposed merger.
The application, which includes seven amendments, has been criticized for being overly complex and difficult to interpret, with critical information buried in appendices and back-up spreadsheets.

The officials have expressed concerns that the merger could reduce competitive options for shippers, increase costs for businesses, and raise prices for consumers.
The lack of analysis on future industry consolidation and its potential effects is also a major concern, as well as the omission of plans for jointly owned lines.
The partners failed to detail plans for jointly owned lines including the Kansas City Terminal Railway, the Terminal Railroad Association of St. Louis, and railcar pool TTX.
This has led to calls for greater transparency in the application process, with regulators under pressure to ensure that the merger does not harm competition or consumer interests.
The Surface Transportation Board is expected to rule on the application this week, following a May 8 deadline for comments.
The officials have asked the regulator to waive the deadline due to the volume of submissions by UP-NS, but it remains to be seen whether this will happen.
Ultimately, the outcome of the merger application will depend on the ability of regulators to balance the interests of different stakeholders and ensure that the merger is in the public interest.
The lack of transparency in the application process is a concern for regulators, who must ensure that the merger does not harm competition or consumer interests.
