Network TV news representatives will confer Monday to hash out demands about access to Donald Trump’s presidential campaign after Trump officials last week threatened to “blacklist” reporters who left a designated media “pen” during rallies for the presidential front-runner.

According to people at multiple networks, senior managers from the five leading TV news networks — ABC News, CBS News, CNN, Fox and NBC News — will discuss their response in an effort to push back against what they deem harsh and restrictive behavior by Trump’s managers, including his top aide, campaign manager Corey Lewandowski.

Lewandowski threatened to pull the press credentials of a CNN reporter, Noah Gray, last week after Gray sought to leave the press pen during a Trump campaign appearance in Worcester, Mass. Gray, an “embed” for the network who has covered Trump for months, recorded Lewandowski’s threat to “blacklist” him and posted it online.