By now you've surely heard about the massive merger between Bayer and Monsanto that will see the German drug and crops chemical giant buyout the world's largest seeds firm for $66 billion. What you may not know, however, is the politics that surround the two companies as they seek regulatory approval for the merger.

Massive takeovers like this one draw a lot of scrutiny from government regulators, especially when they involve a U.S. company being sold to a foreign entity. Right now in the same industry, Dow Chemical  and DuPont face an uphill battle to get their own merger approved, while Syngenta's sale to ChemChina was recently approved after several U.S. senators urged the government to dissect the deal.

Over the next few weeks or months, government officials will investigate the Bayer-Monsanto deal to determine whether it would breach antitrust regulations or negatively impact food safety and supply. As that process plays out, it's important to remember that corporations like Bayer and Monsanto spend quite a bit of money to ensure that the government sides with them in moments like this.

Interestingly enough, these two companies in particular are known for their political spending. According to OpenSecrets , a non-partisan research firm dedicated to government accountability, Monsanto has spent nearly $2.5 million on lobbying efforts this year, making it the biggest spender in the agricultural industry. Bayer is the eighth-highest spender in the pharmaceuticals industry and has spent over $3.6 million on lobbying so far this year.

And it's not like both companies decided to start lobbying the government in anticipation of this big merger. In fact, both companies have a long history of political spending; over the past decade, Bayer and Monsanto have spent a combined $120 million on lobbying.

Throughout the past few years, the focus of both companies' lobbying efforts has centered on the labeling of genetically modified foods. Bayer and Monsanto supported the Safe and Accurate Food Labeling Act of 2015, a bill that critics claim makes it harder for shoppers to interpret GMO information on food labels.

Of course, all the lobbying in the world doesn't necessarily matter when the company lawyers sit down with officials from the Justice Department, the regulatory body that will be tasked with investigating the merger.