AT&T's $85.4bn (£70bn) deal to acquire Time Warner has raised antitrust and anti-competition concerns. Apart from US lawmakers, both presidential candidates Donald Trump and Hillary Clinton have raised questions about this deal, which could potentially be the largest transaction this year.

The Republican presidential nominee said he would block the takeover deal. "As an example of the power structure I'm fighting, AT&T is buying Time Warner and thus CNN, a deal we will not approve in my administration because it's too much concentration of power in the hands of too few," Trump had said on Saturday while making a speech in Pennsylvania.

Meanwhile, Clinton spokesman Brian Fallon said the deal involved "a number of questions and concerns". He added that more information should be known "before any conclusions should be reached", the Guardian reported.

Apart from them, Mike Lee, chairman of the US Senate committee on antitrust said on Sunday (23 October) that it would look into the AT&T takeover plan. "[The deal would] potentially raise significant antitrust issues, which the subcommittee would carefully examine."

The concern over competition is said to be that the combined company would offer consumers lesser choice but charge them higher prices. The committee is said to hold a hearing on the same in November.

Competition lawyer Amanda Wait from Hunton & Williams said this was not a straightforward issue. "The anti-trust division here in the US is going to have to take a hard look at how this deal changes AT&T's incentives and that's a really complicated question," she was quoted as saying by the BBC.

The two main issues according to Wait were if AT&T would now gain to withhold Game Of Thrones from other cable providers and if it would favour its own content over others. "Is AT&T going to have an incentive to make HBO and other Time Warner channels more visible, more easily accessible on [AT&T's] various service networks and dis-favour, or maybe even hide, the other channels that it's carrying?" she said.

However, on the other hand, the heads of both AT&T and Time Warner have rebuffed claims that their deal might be blocked. They said both the companies made a "perfect match".

Randall Stephenson, AT&T's chief executive, further said there is "no competitive harm that is being rendered by putting these two companies together". He was cited by the Telegraph as explaining, "The deal] is a vertical merger in its pure sense. We are combining with a supplier".