Years of political plotting, fierce backlashes, and cliffhangers. No, this isn't your favourite dragon-themed fantasy drama, this is the M4 relief road. With Mark Drakeford set to announce his decision on Tuesday, we take a look back at some of the important moments leading up to this point.

Original plans to construct a relief road were announced in 1991 an ultimately shelved in 2009. You can read about those events here.

­— September 2013

The Welsh Government announces a consultation period as part of its plans to improve and extend the M4. Among its proposals is the so-called Black Route, which would involve the construction of a brand-new stretch of motorway south of Newport between Junction 23A (Magor) and Junction 29 (Castleton).

The route would include building on a section of the Gwent Levels.

The consultation period is set to run until December 16.

­— November 2013

Prime Minister David Cameron and his deputy, Nick Clegg, visit the Senedd and announce Wales will get the borrowing and taxation powers needed to get the relief road built.

The landfill tax and stamp duty land tax will be devolved, it is announced, to help fund the borrowing with Mr Cameron saying the M4 was like “a foot on the windpipe of the Welsh economy”.

The prospect of added revenue means the Welsh Government will now likely be able to afford a project that was dropped in 2009 due to cost.

The news is welcomed by many in the business community, with Emma Watkins, director of the Confederation of Business Industry (CBI) Wales, calling it “a major day for Wales”.

“The M4 is the gateway to Wales, and this upgrade will bring clear benefits for both businesses and commuters, and enhance Wales’ position on the global map,” she adds.

­— January 2014

Newport City Council responds to the M4 consultation by saying it backs the proposed Black Route.

But the council wants a minimum of three junctions in Newport to ensure the city isn’t bypassed “to the detriment of its economic growth and regeneration”, a report says.

­— July 2014

Edwina Hart, Wales’ economy, science and transport minister, announces that the Welsh Government is backing the Black Route proposal.

“The M4 project is of vital importance to the economic prosperity of the country as a whole,” a Welsh Government spokesman says after the announcement.

“In the past, we were unable to progress the scheme because it was simply unaffordable – but thanks to the new borrowing powers we have secured, we can now take forward this and other vital schemes.”

­— March 2015

The Association of British Ports (ABP) says the Black Route will affect the future development of Newport Docks.

Director of ABP South Wales, Matthew Kennerley, says: “We are not for or against any specific alternative proposals for the route of a new M4 Relief Road, but we do feel strongly that all options should be fully explored before an irrevocable decision is taken on a route that could seriously harm one of Wales’ most strategically important ports.”

­— May 2016

Roadchef, which runs Magor Services – Wales’ busiest service station – weighs in on the debate.

The firm’s boss Simon Turl says the company could lose up to 80 per cent of its business, threatening up to 190 jobs.

“We’ve attempted to engage with the Welsh government over the past year, but they have neglected to take these factors into consideration in their consultation,” Mr Turl says.

­— October 2016

Welsh transport minister Ken Skates criticises the UK Department for Transport (DfT) after revealing a public inquiry into the relief road scheme – previously scheduled for November – will be put on hold until the following year.

Mr Skates calls the delay “hugely disappointing” and blames the DfT for introducing a new method of predicting traffic volumes without first telling the Welsh Government.

"The public deserve an explanation for this,” he says. "I don't believe there is a conspiracy against Wales, but I do believe there is incompetence."

The DfT refutes the claims.

The public inquiry is given a new start date, with a deadline of March 2017.

­— April 2017

The relief road inquiry hears how Severnside residents fear being “swamped” if the Black Route goes ahead.

The Welsh government has “not adequately” addressed their concerns of noise and air pollution on their quality of life, they say.

­— February 2018

As the inquiry reaches its end, it hears how the cost of the Black Route is now estimated at topping £1.3 billion.

Amid tussling over predicted costs, the issue of the Severn Bridge tolls is brought up.

Traffic consultant and Welsh Government witness Bryan Whittaker tells the inquiry that removal of the Severn tolls would aggravate congestion problems around J23 and J23A (Magor Services), where the Black Route is proposed to begin.

­— May 2018

Mark Drakeford, who is running to replace Carwyn Jones as first minister, says he will consider backing a cheaper relief road scheme.

He tells the BBC: "I'm the finance minister in the Welsh Government. If we could have a solution that cost us less then of course that would be attractive to me, because there's always other things we would be able to do with that money.”

­— September 2018

Wales’ future generations commissioner, Sophie Howe, presents an alternative proposal, investing in public transport rather than building a new motorway.

Ms Howe brands the Black Route scheme “unambitious”.

Her plan is praised by campaigners living on the fringes of the proposed route, as well as environmental campaigners.

But some business leaders are less impressed.

“The message on improving the M4 is clear: get it done and get it done quickly,” Robert Lloyd Griffiths, head of IoD Wales (The Institute of Directors), says.

­— March 2019

An anti relief-road petition gathers 20,000 signatures.

The petition calls on First Minister Mark Drakeford to abandon the Black Route project through the Gwent Levels, dubbed the ‘Amazon rainforest of Wales’.

Mr Drakeford has already announced that his decision will be made after the Newport West by-election, scheduled for April 4.

­— June 2019

First Minister Mark Drakeford is scheduled to make his decision on Tuesday, June 4.