The Financial Times reports that Haines called the deal “one of the most significant threats to our operations at present,” and said that the combined business would have had a 93% share of the British signalling market in 2016-17.

The paper reported that Hanies said if the merger could not be prohibited, “the only possible remedy that could restore competition to pre-merger levels is an appropriate structural divestment” through the sale of the elements which previously made up Invensys, which Siemes acquired for $US 2.8bn in 2013.

A Network Rail spokesman confirmed to IRJ that the Financial Times story was factual but said Network Rail would not comment further.

The EC launched a detailed review of the planned merger in July, citing concerns that the combination of the two businesses could lead to “higher prices, less choice and less innovation due to reduced competitive pressure in rolling stock and signalling tenders.”

In July Britain’s rail regulator, the Office of Rail and Road (ORR), claimed that the combination “will significantly reduce competition, leading to increased costs in Britain’s railway signalling and rolling stock markets.” The ORR also believes that “arguments over the scale and significance of Chinese entry, which have been widely cited as a justification for the merger, have been over-exaggerated.”